AP PHYSICS FINAL

Object 1 is moving along the x axis with an initial momentum +16 kg·m/s, where the + sign indicates that it is moving to the right. As the drawing shows, object 1 collides with a second object that is initially at rest. The collision is not head-on, so the objects move off in different directions after the collision. The net external force acting on the two-object system is zero. After the collision, object 1 has a momentum whose x component is +6 kg·m/s. What is the x-component of the momentum of object 2 after the collision?

+10 kg·m/s

Object 1 is moving along the x axis with an initial momentum +16 kg·m/s, where the + sign indicates that it is moving to the right. As the drawing shows, object 1 collides with a second object that is initially at rest. The collision is not head-on, so the objects move off in different directions after the collision. The net external force acting on the two-object system is zero. After the collision, object 1 has a momentum whose y component is -5 kg·m/s. What is the y-component of the momentum of object 2 after the collision?

+5 kg·m/s

Four very thin rods, each 6.8 m long, are joined to form a square, as part (a) of the drawing shows. The center of mass of the square is located at the coordinate origin. The rod on the right is then removed, as shown in part (b) of the drawing. What are the x- and y-coordinates of the center of mass of the remaining three-rod system?

-1.133m, 0m

A 92.0-kg skydiver falls straight downward with an open parachute through a vertical height of 325 m. The skydiver's velocity remains constant. What is the work done by the nonconservative force of air resistance, which is the only nonconservative force acting?

-2.93 × 10^5 J

Consider the force F shown in the drawing. This force acts on an object that can move along the positive or negative x axis, or along the positive or negative y axis. The work done by this force is positive when the displacement of the object is along the __________ axis or along the __________ axis.

-x, +y

What is the wavelength λ of a wave that has a speed of 160 m/s and a period of 4.6 ms?

.736 m

The frequency and wavelength of a transverse wave on a string are 340 Hz and 0.70 m, respectively. The tension in the string is 130 N. What is the linear density of the string?

0.0022 kg/m

An object on a vertical spring oscillates up and down in simple harmonic motion with an angular frequency of 17.3 rad/s. Calculate the distance d by which the spring stretches from its unstrained length when the object is allowed to hang stationary from it.

0.032 m

A 0.20-kg object is attached to the end of an ideal horizontal spring that has a spring constant of 120 N/m. The simple harmonic motion that occurs has a maximum speed of 1.2 m/s. Determine the amplitude A of the motion.

0.0489 m

A block weighs 15 N and is suspended from a spring that is attached to the ceiling. The spring stretches by 0.075 m from its unstrained length. By how much does the spring stretch when a 37-N block is suspended from it?

0.185 m

A 30-N crate is suspended from the left end of a plank. The plank weighs 21 N, but it is not uniform, so its center of gravity does not lie halfway between the two ends. The system is balanced by a support that is 0.30 m from the left end of the plank. How far to the right of the support is the plank's center of gravity?

0.4285 m

A diver in midair has an angular velocity of 6.0 rad/s and a moment of inertia of 1.3 kg·m2. He then pulls is arms and legs into a tuck position and his angular velocity increases to 12 rad/s. The net external torque acting on the diver is zero. What is his moment of inertia in the tuck position?

0.65 kg*m/s^2

A small cylinder rests on a circular turntable that is rotating clockwise at a constant speed. The cylinder is at a distance of r = 12 cm from the center of the turntable. The coefficient of static friction between the bottom of the cylinder and the surface of the turntable is 0.45. What is the maximum speed vmax that the cylinder can have without slipping off the turntable?

0.73 m/s

Two transverse standing waves are shown in the drawing. The wavelength of the standing wave at the top is 1.2 m. What is the wavelength of the one at the bottom?

0.8 m

A longitudinal standing wave is established in a tube that is open at both ends (see the drawing). The length of the tube is 0.80 m. What is the wavelength of the waves that make up the standing wave?

0.80 m

Two wires are made from the same material. One wire has a resistance of 0.10 Ω. The other wire is twice as long as the first wire and has a radius that is half as much. What is the resistance of the second wire?

0.80 Ω

A car is rounding an unbanked circular turn with a speed of v = 35 m/s. The radius of the turn is r = 1500 m. What is the magnitude ac of the car's centripetal acceleration?

0.82 m/s^2

In 3.7 s, 1.9 × 1019 electrons pass a certain point in a wire. What is the current I in the wire?

0.8216 A

A hoop is rolling (without slipping) on a horizontal surface so it has two types of kinetic energy: translational kinetic energy and rotational kinetic energy. The entire mass M of the hoop is concentrated at its rim, so its moment of inertia is I = MR2, where R is the radius. What is the ratio of the translational kinetic energy to the rotational kinetic energy?

1

Rank the particles according to the magnitude of the centripetal force that acts on them, largest first.

1 2 3

The drawing shows four moving pulses. Although shown as separated, the four pulses exactly overlap each other at the instant shown. Which combination of these pulses would produce a resultant pulse with the highest peak and the deepest valley at this instant?

1 and 2

The drawing shows four moving pulses. Although shown as separated, the pulses may exactly overlap each other at the instant shown. Which combination of these pulses would produce a horizontal straight line at this instant?

1 and 4

A particle is moving along the +x axis, and the graph shows its momentum p as a function of time t. What is the magnitude of the net average force in regions A and C?

1.0 N, 4.0 N

The radius of each wheel on a bicycle is 0.400 m. The bicycle travels a distance of 3.0 km. Assuming that the wheels do not slip, how many revolutions does each wheel make?

1.2 × 10^3 revolutions

Two cellists, one seated directly behind the other in an orchestra, play the same 220-Hz note for the conductor who is directly in front of them. What is the smallest non-zero separation that produces constructive interference? Take the speed of sound to be 343 m/s.

1.559 m

The period of a simple pendulum is 1.2 s. The length of the pendulum is doubled. What is the period T of the longer pendulum?

1.697 s

The drawing shows two blocks that are placed at the ends of a massless board. The board is balanced on a support that serves as an axis of rotation. The block on the left has a mass of 8.6 kg. What is the moment of inertia of this system about the axis of rotation?

1.754 kg*m/s^2

A meter stick is rotated about the end labeled 0.00 cm, so that the other end of the stick moves through an arc length of 7.59 cm. Through what arc length s does the 25.0-cm mark on the stick move?

1.8975 cm

The drawing shows three particles that are moving with different velocities. Two of the particles have mass m, and the third has a mass 2m. The third particle has a velocity of v3 = +5.9 m/s. At the instant shown, the center of mass (cm) of the three particles is at the coordinate origin. What is the velocity vcm (magnitude and direction) of the center of mass?

1.95m/s along +x axis

The moon is a satellite that orbits the earth at a radius of 3.85 × 108 m. The mass of the earth is 5.98 × 1024 kg. What is the orbital speed of the moon?

1020 m/s

In being served, a tennis ball is accelerated from rest to a speed of 49.7 m/s. The average power generated during the serve is 2920 W. Assuming that the acceleration of the ball is constant during the serve, find the force acting on the ball.

117.505 N

Three forces are applied to a solid cylinder of mass 12 kg (see the drawing). The magnitudes of the forces are F1 = 15 N, F2 = 24 N, and F3 = 15 N. The radial distances are R2 = 0.22 m and R3 = 0.10 m. The forces F2 and F3 are perpendicular to the radial lines labeled R2 and R3. The moment of inertia of the cylinder is one-halfUpper M Upper R Subscript 2 Superscript 2. Find the magnitude of the angular acceleration of the cylinder about the axis of rotation.

13.0165 rad/s^2

The drawing shows a top view of a hockey puck as it slides across frictionless ice. Three forces act on the puck, and it is in equilibrium. The force F is applied at the center and has a magnitude of 40 N. The force F1 is applied at the top edge, and F2 is applied half way between the center and the bottom edge. Find the magnitude of F1 and F2.

13.333N 26.666 N

A 3.00-kg model airplane has velocity components of 5.00 m/s due east and 8.00 m/s due north. What is the plane's kinetic energy?

134 J

A platform is rotating with an angular speed of 3.00 rad/s and an angular acceleration of 11.0 rad/s2. At a point on the platform that is 1.09 m from the axis of rotation, what is the magnitude of the total acceleration a?

15.4918 m/s^2

A 1220-kg car starts from rest at the bottom of a drive way and has a speed of 3.00 m/s at a point where the drive way has risen a vertical height of 0.600 m. Friction and the drive force produced by the engine are the only two nonconservative forces present. Friction does -2870 J of work. How much work does the engine do?

15533.6 J

A hot-air balloon is 11.0 m above the ground and rising at a speed of 7.00 m/s. A ball is thrown horizontally from the balloon basket at a speed of 9.00 m/s. Ignore friction and air resistance and find the speed of the ball when it strikes the ground.

18.6 m/s

The drawing shows an extreme skier at three locations on a ski run: (A) a straight section, (B) a circular section, and (C) an airborne phase in which the skier is in free-fall. At the right of the drawing are four possible directions for the net force that acts on the skier. What is the direction of the net force at A, B, and C? Assume that there is no friction or air resistance at any point along the ski run.

2 1 3

An object in simple harmonic motion has an amplitude of 0.264 m and an oscillation period of 0.620 s. Determine the maximum speed of the motion.

2.6754 m/s

A rotating wheel has a constant angular acceleration. It has an angular velocity of 5.0 rad/s at time t = 0 s, and 3.0 s later has an angular velocity of 9.0 rad/s. What is the angular displacement of the wheel during the 3.0-s interval?

21 rad

The frequency of the longitudinal standing wave shown in the drawing is 440 Hz. The tube is open at both ends. What is the fundamental frequency of the tube?

220 Hz

A small fan has blades that have a radius of 0.0600 m. When the fan is turned on, the tips of the blades have a tangential acceleration of 13.5 m/s2 as the fan comes up to speed. What is the angular acceleration α of the blades?

225 rad/s^2

The drawing shows a top view of a door that is free to rotate about an axis of rotation that is perpendicular to the screen. Find the net torque (magnitude and direction) produced by the forces F1 and F2 about the axis.

23.3 N·m, counterclockwise

The radius of the circle traced out by the second hand on a clock is 6.00 cm. In a time t the tip of the second hand moves through an arc length of 15.0 cm. Determine the value of t in seconds.

23.873 s

The drawing shows a plot of the force component F cos θ in the direction of the displacement s for one particular variable force, between a displacement of s = 0 m and s = d. What is the work done by the force when d = 2.64 m?

248.16 J

The transverse standing wave on a string fixed at both ends is vibrating at its fundamental frequency of 250 Hz. What would be the fundamental frequency on a piece of the same string that is twice as long and has four times the tension?

250 Hz

Three forces act simultaneously on a 2.70-kg block. For clarity the drawings show the forces separately. The block starts from rest and, as a result of the combined action of the forces, undergoes a displacement s, which has a magnitude of 6.50 m. What is the final speed of the block?

27.1 m/s

Two blocks are placed at the ends of a horizontal massless board, as in the drawing. The board is kept from rotating and rests on a support that serves as an axis of rotation. The block on the right has a mass of 2.9 kg. Determine the magnitude of the angular acceleration when the system is allowed to rotate.

3.075 rad/s^2

A merry-go-round at a playground is a circular platform that is mounted parallel to the ground and can rotate about an axis that is perpendicular to the platform at its center. The angular speed of the merry-go-round is constant, and a child at a distance of 1.4 m from the axis has a tangential speed of 2.2 m/s. What is the tangential speed of another child, who is located at a distance of 2.1 m from the axis?

3.3 m/s

A high-jumper clears the bar and has a downward velocity of -6.00 m/s just before landing on an air mattress. The mass of the high-jumper is 52.3 kg. What is the magnitude and direction of the impulse that the air mattress exerts on her? Assume that upward is the positive direction.

313.8 kg*m/s

Each tire on a car has a radius of 0.330 m and is rotating with an angular speed of 16.6 revolutions/s. Find the linear speed v of the car, assuming that the tires are not slipping against the ground.

34.4192 m/s

A small cylinder rests on a circular turntable that is rotating clockwise at a constant speed. Which set of vectors gives the direction of the velocity v and acceleration a of the cylinder, and the net force ΣF that acts on it.

4

Five hockey pucks are sliding across frictionless ice. The drawing shows a top view of the pucks and the three forces that act on each one. The forces can have different magnitudes (F, 2F, or 3F), and can be applied at different points on the puck. Only one of the five pucks could be in equilibrium. Which one?

4

The car in the left drawing is moving counterclockwise with a constant speed v around a circular section of the road. The drawing at the right shows the car and four possible directions for the centripetal acceleration that it experiences. Which one (if any) depicts the correct direction for the centripetal acceleration?

4

Two identical resistors are connected first in series and second in parallel. The equivalent resistances of the two types of connections are, respectively, RS and RP. What is the ratio RS/RP?

4

A rigid rod is rotating at a constant angular speed about an axis that is perpendicular to one end of the rod. A small ball is fixed to the rod at a distance that is 12 cm from the axis. The centripetal force acting on this ball is 1.7 N. What would be the centripetal force that acts on the ball if the ball were fixed to the rod at a distance of 33 cm from the axis?

4.7 N

A rotating object starts from rest at t = 0 s and has a constant angular acceleration. At a time of t = 7.0 s the object has an angular velocity of ω = 23 rad/s. What is its angular velocity at a time of t = 14 s?

46 rad/s

The power needed to accelerate a projectile from rest to its launch speed v in a time t is 59.6 W. How much power is needed to accelerate the same projectile from rest to a launch speed of 2v in a time of 1/2t?

476.8 W

A transverse wave on a string has an amplitude A. A tiny spot on the string is colored red. As one cycle of the wave passes by, what is the total distance traveled by the red spot?

4A

A bicycle rider has a speed of 19.0 m/s at a height of 55.0 m above sea level when he begins coasting down hill. The mass of the rider and his bike is 88.0 kg. Sea level is the zero level for measuring gravitational potential energy. Ignoring friction and air resistance, what is the rider's total mechanical energy when he coasts to a height of 25.0 m above sea level?

6.33 × 10^4 J

A 2.60-kg block is attached to a horizontal spring that has a spring constant of 155 N/m. At the instant when the displacement of the spring from its unstrained length is -0.115 m, what is the acceleration a of the object? In your answer, be sure to include the proper plus or minus sign.

6.855 m/s^2

Two identical cars (m = 1350 kg) are traveling at the same speed of 35.6 m/s. They are moving in the directions shown in the drawing. What is the magnitude of the total momentum of the two cars?

67967.1038 kg*m/s

A 12.4-kg box is being pushed from the bottom to the top of a frictionless ramp. When the box is pushed at a constant velocity, the nonconservative pushing force does 58.0 J of work. How much work is done by the pushing force when the box starts from rest at the bottom and reaches the top of the same ramp with a speed of 1.50 m/s?

71.95 J

A force does +130 J of work when it acts on a moving object and its direction is in the same direction as the object's displacement. How much work does this force do when the angle between it and the object's displacement is 56°?

72.695 kg*m/s^2

Starting from rest at the top, a child slides down the water slide at a swimming pool and enters the water at a final speed of 5.71 m/s. At what final speed would the child enter the water if the water slide were twice as high? Ignore friction and resistance from the air and the water lubricating the slide.

8.075 m/s

A rotating object starts from rest at t = 0 s and has a constant angular acceleration. At a time of t = 2.5 s the object has an angular displacement of 20 rad. What is its displacement θ at a time of t = 5.0 s?

80 rad

A 1650-kg car is traveling at 22.4 m/s. How fast must a 91.0-kg bicycle and rider be traveling to have the same kinetic energy as the car?

95.3826 m/s

An external force (in addition to the spring force) is continually applied to an object of mass m attached to a spring that has a spring constant k. The frequency of this external force is such that resonance occurs. Then the frequency of this external force is doubled, and the force is applied to one of the spring systems shown in the drawings. With which one would resonance occur?

A

The drawings show a number of different possibilities for connecting an ammeter (AM) and a voltmeter (VM) to a circuit, in order to measure the current in and the voltage across the resistor labeled R2. Which one of the possibilities shows the correct connections?

A

A single resistor is connected across the terminals of a battery. Which one or more of the following changes in voltage and current leaves unchanged the electric power dissipated in the resistor? (A) Doubling the voltage and reducing the current by a factor of two. (B) Doubling the voltage and increasing the resistance by a factor of four. (C) Doubling the current and reducing the resistance by a factor of four.

A B C

A toy car (0.50 kg) runs on a frictionless track and has an initial kinetic energy of 2.2 J, as the drawing shows. The numbers beneath each hill give the heights of the hills. Over which of the hills will the car coast?

A B C and D

The drawing shows three objects rotating about a vertical axis. The mass of each object is given in terms of m0, and its perpendicular distance from the axis is specified in terms of r0. Rank the three objects according to their moments of inertia, largest to smallest.

A C B

The kinetic energy of an object attached to a horizontal ideal spring is denoted by KE and the elastic potential energy by PE. For the simple harmonic motion of this object the maximum kinetic energy and the maximum elastic potential energy during an oscillation cycle are KEmax and PEmax, respectively. In the absence of friction, air resistance, and any other nonconservative forces, which of the following equations applies to the object-spring system? A. KE + PE = constant B. KEmax = PEmax

A and B

A rotating object has an angular acceleration of α = 0 rad/s2. Which one or more of the following three statements is consistent with a zero angular acceleration?

A and B, but not C

A particle is moving along the +x axis, and the graph shows its momentum p as a function of time t. Use the impulse-momentum theorem and rank (largest to smallest) the three regions according to the magnitude of the impulse applied to the particle.

A and C (a tie), B

A rotating object has an angular acceleration α that is not zero. Which one or more of the following three statements is consistent with a non-zero angular acceleration?

A and C, but not B

Six runners have masses (in multiples of m0), speeds (in multiples of v0) and travel in the directions indicated in the table. Which two runners have identical momenta?

A and E

In which one of the following circumstances could mechanical energy not possibly be conserved, even if friction and air resistance are absent?

A car moves up a hill at a constant velocity.

Five simple pendulums are shown in the drawings. The lengths of the pendulums are drawn to scale, and the masses are either m or 2m, as shown. Which one has the smallest angular frequency of oscillation?

B

The following four equations are supposed to result from applying Kirchhoff's junction rule to the four junctions in the circuit shown in the drawing. However, one of the equations is written incorrectly. Which one is it?

B

In the following three arrangements each resistor has the same resistance R. Rank the equivalent resistances of the arrangements in descending order (largest first).

B C A

Two hoops, starting from rest, roll down identical inclined planes. The work done by nonconservative forces, such as air resistance, is zero (Wnc = 0 J). Both have the same mass M, but, as the drawing shows, one hoop has twice the radius as the other. The moment of inertia for each hoop is I = Mr2, where r is its radius. Which, if either, has the greater total kinetic energy (translational plus rotational) at the bottom of the incline?

Both have the same total kinetic energy.

Which one of the following graphs correctly represents Ohm's law, where V is the voltage and I is the current?

C

A particle is moving along the +x axis, and the graph shows its momentum p as a function of time t. In each of the four regions a force, which may or may not be nearly zero, is applied to the particle. In which region is the magnitude of the force largest and in which region is it smallest?

C (largest), B (smallest)

The same force F pushes in three different ways on a box moving with a velocity v, as the drawings show. Rank the work done by the force F in ascending order (smallest first).

C A B

Two cars are traveling at the same constant speed v. Car A is moving along a straight section of the road, while B is rounding a circular turn. Which statement is true about the acceleration of the cars?

Car A is not accelerating, but car B is accelerating.

An object is oscillating in simple harmonic motion with an amplitude A and an angular frequency ω. What should you do to increase the maximum acceleration of the motion?

Decrease A by 10% and increase ω by 10%.

Under what condition(s) is the angular momentum of a rotating body, such as a spinning ice skater, conserved?

Each external torque may be non-zero, but the sum of the torques must be zero.

The meter stick in the drawing can rotate about an axis located at the 20.0-cm mark. The axis is perpendicular to the screen. A force F acts at the left end; the force is perpendicular to the meter stick and has a magnitude of 175 N. A second force, either F1 or F2, acts at the 80.0-cm mark, as the drawing shows. The meter stick is in equilibrium. Which force, F1 or F2, acts on the meter stick, and what is its magnitude?

F2, magnitude = 71.2 N

The drawing shows an extreme skier at bottom of a ski jump. At this point the track is circular with a radius r. Two forces act on the skier, her weight mg and the normal force FN. Which relation describes how the net force acting on her is related to her mass m and speed v and to the radius r? Assume that "up" is the positive direction.

FN - mg = m^2/r

The space station in the drawing is rotating to create artificial gravity. The speed of the inner ring is one half that of the outer ring. As an astronaut walks from the inner to the outer ring, what happens to her apparent weight?

Her apparent weight becomes twice as great.

For the circuit shown in the drawing, what is the ratio of the current I1 in resistor R1 to the current I2 in resistor R2?

I1/I2 = R2/R1

Which one of the following equations results from a correct application of Kirchhoff's loop rule to loop ABDEF in the circuit shown in the drawing?

I1R1 + I2R2 + I4R4 = 2.0V

What is the difference between transverse and longitudinal waves?

In a transverse wave the disturbance always occurs perpendicular to the direction in which the wave travels, whereas in a longitudinal wave the disturbance always occurs parallel to the line of travel of the wave.

An object is oscillating in simple harmonic motion with an amplitude A and an angular frequency ω. What should you do to increase the maximum speed of the motion?

Increase both A and ω by 10%.

The drawing shows an object attached to an ideal spring, which is hanging from the ceiling. The unstrained length of the spring is indicated. For purposes of measuring the height h that determines the gravitational potential energy, the floor is taken as the position where h = 0 m. The equilibrium position at which the object hangs stationary is identified as position 2. The object is set into vertical simple harmonic motion between positions 1 and 3. Identify the positions where the kinetic energy KE, the elastic potential energy EPE, and the gravitational potential energy GPE each have their maximum values during an oscillation cycle.

KE is has a maximum value at position 2. EPE has a maximum value at position 3. GPE has a maximum value at position 1.

The table lists the initial and final kinetic and potential energies for a number of different motions. Identify the one for which mechanical energy is not conserved by determining the work Wnc done by the net nonconservative force.

Motion D, Wnc = -465 J

Two objects are involved in a completely inelastic one-dimensional collision. The net external force acting on them is zero. The table lists four possible sets of the initial momenta and kinetic energies of the two objects, as well as their final momenta and kinetic energies. Which is the only set that could occur?

Object 1: -3 kg*m/s 1 J Object 2: +4 kg*m/s 6 J +1 kg*m/s 4J

As the text discusses, the conservation of linear momentum is applicable only when the system of objects is an isolated system. Which of the systems listed below are isolated systems?

Only 2 and 5 are isolated systems.

When applying Kirchhoff's rules, one of the essential steps is to mark each resistor with plus and minus signs to label how the potential changes from one end of the resistor to the other. The circuit in the drawing contains four resistors, each marked with the associated plus and minus signs. However, one resistor is marked incorrectly. Which one is it?

R4

The drawing shows identical stones that are being whirled on a tabletop at the same speed. The radius of the larger circle is twice that of the smaller circle. How is the tension T1 in the longer cord related to the tension T2 in the shorter cord?

T1 = one-halfT2

A high-jumper, having just cleared the bar, lands on an air mattress and comes to rest. Had she landed directly on the hard ground, her stopping time would have been much shorter. Using the impulse-momentum theorem as your guide, determine which one of the following statements is correct.

The air mattress exerts the same impulse, but a smaller net average force, on the high-jumper than does the hard ground.

A block is attached to a horizontal spring. On top of this block rests another block. The two-block system slides back and forth in simple harmonic motion on a frictionless horizontal surface. At one extreme end of the oscillation cycle, when the blocks come to a momentary halt, the top block is liften vertically upward, without disturbing the bottom block. What happens to the amplitude and the angular frequency of the ensuing motion?

The amplitude remains the same, and the angular frequency increases.

A ball is fixed to the end of a string, which is attached to the ceiling at point P. As the drawing shows, the ball is projected downward at A with the launch speed v0. Traveling on a circular path, the ball comes to a halt at point B. What enables the ball to reach point B, which is above point A? Ignore friction and air resistance.

The ball's initial kinetic energy.

The wheels on a moving bicycle wheel have both translational (or linear) and rotational motions. What is meant by the phrase "a rigid body, such as a bicycle wheel, is in equilibrium?"

The body can have translational and rotational motions, as long as its translational acceleration and angular acceleration are zero.

The drawing shows a top view of a square box lying on a frictionless floor. Three forces, which are drawn to scale, act on the box. Consider an angular acceleration with respect to an axis through the center of the box (perpendicular to the screen). Which one of the following statements is correct?

The box will have an angular acceleration, but not a translational acceleration.

Two identical cars, one on the moon and one on the earth, have the same speed and are rounding banked turns that have the same radius r. There are two forces acting on each car, its weight mg and the normal force FN exerted by the road. Recall, that the weight of an object on the moon is about one sixth of its weight on earth. How does the centripetal force on the moon compare with that on earth?

The centripetal forces are the same.

A force F acts on an object undergoing a displacement s, the force being oriented at an angle θ with respect to the displacement. Which one of the following correctly describes ALL of the circumstances under which the work done by the force is zero?

The force is zero, or the displacement is zero, or the angle is 90°.

A horn on a boat sounds a warning, and the sound penetrates the water. How does the frequency of the sound in the air compare to its frequency in the water? How does the wavelength in the air compare to the wavelength in the water?

The frequency in the air is the same as the frequency in the water, and the wavelength in the air is smaller than the wavelength in the water.

A car is rounding a circular curve of radius r on a banked turn. As the drawing indicates, there are two forces acting on the car, its weight mg and the normal force FN exerted on it by the road. Which force, or force component, provides the centripetal force that keeps the car moving on the circular path?

The horizontal component, FNsinθ of the normal force.

A nonzero net force acts on a particle and does work. Which one of the following statements is true?

The kinetic energy, speed, and velocity of the particle change.

Two cars are driving at the same constant speed v around a racetrack. However, they are traveling through turns that have different radii, as shown in the drawing. Which statement is true about the magnitude of the centripetal acceleration of each car?

The magnitude of the centripetal acceleration of the car at A is greater than that of the car at B, since the radius of the circular track is smaller at A.

In which one of the following circumstances does the principle of conservation of mechanical energy apply, even though a nonconservative force acts on the moving object?

The nonconservative force is perpendicular to the displacement of the object.

You have two springs. One has a greater spring constant than the other. You also have two objects, one with a greater mass than the other. Which object should be attached to which spring, so that the resulting spring-object system has the greatest possible period of oscillation?

The object with the greater mass should be attached to the spring with the smaller spring constant.

Two cellists, one seated directly behind the other in an orchestra, play the same note for the conductor who is directly in front of them. Because of the separation between the cellists, destructive interference occurs at the conductor. This separation is the smallest that produces destructive interference. Would this separation increase, decrease, or remain the same if the cellists produced a note with a higher frequency?

The separation would decrease because the wavelength of the sound is smaller.

The same force F is applied to the edge of two hoops. The hoops have the same mass, although the radius of the larger hoop is twice that of the smaller one. The entire mass of each hoop is concentrated at its rim, so the moment of inertia is I = Mr2, where M is the mass and r is the radius. Which hoop has the greater angular acceleration, and how many times as great is it compared to that of the other hoop?

The smaller hoop; two times as great.

Which one of the following statements describes the condition(s) for which a rigid body is in equilibrium?

The sum of the externally applied forces must be zero, and the sum of the externally applied torques must be zero.

Two transverse standing waves are shown in the drawing. The strings have the same tension and length, but the bottom string is more massive. Which standing wave, if either, is vibrating at the higher frequency?

The top standing wave has the higher frequency because the traveling waves have a larger speed due to the smaller mass of the string.

A small-amplitude transverse wave is traveling on a string. The frequency of the wave is suddenly doubled. Which one of the following is a true statement?

The wavelength is cut in half.

A standing wave on a string fixed at both ends is vibrating at its 4th harmonic. If the length, tension, and linear density are kept constant, what can be said about the wavelength and frequency of the 5th harmonic relative to the 4th harmonic?

The wavelength of the 5th harmonic is shorter, and its frequency is higher.

Two forces F1 and F2 act on a particle. As a result the speed of the particle increases. Which one of the following is NOT possible?

The work done by each force is negative.

Two identical cars are traveling at the same speed. One is heading due east and the other due north, as the drawing shows. Which statement is true regarding the kinetic energies and momenta of the cars?

They have the same kinetic energies, but different momenta.

For the circuit shown in the drawing, what is the voltage V1 across resistance R1?

V1 = (R1/R2)V

Force F1 acts on a particle and does work W1. Force F2 acts simultaneously on the particle and does work W2. The speed of the particle does not change. Which one of the following must be true?

W1 = W2

A wheel rotates with a constant angular speed ω. Which one of the following is true concerning the angular acceleration α of the wheel, the tangential acceleration aT of a point on the rim of the wheel, and the centripetal acceleration ac of a point on the rim?

a = 0 rad/s2, aT = 0 m/s2, and ac ≠ 0 m/s2

An echo is sound that returns to you after being reflected from a distant surface (e.g., the side of a cliff). Assuming that the distances involved are the same, an echo under water and an echo in air return to you _____________________.

at different times, the echo under water returning more quickly.

Two objects undergo an elastic collision. The table shows four possible sets of the initial and final kinetic energies of the objects. Which is the only set that could occur?

b. 8 J 6 J 10 J 4 J

As the amplitude of a sound wave in air decreases to zero, _________________.

both the condensations and the rarefactions of the wave disappear.

Which one of the following graphs correctly represents the restoring force F of an ideal spring as a function of the displacement x of the spring from its unstrained length?

c

The two objects shown in the drawing are initially moving in opposite directions. They are on a horizontal frictionless surface, so the net external force acting on them is zero. The objects collide and move apart after the collision. The table shows five possible sets of initial and final momenta for the objects. Which is the only set that could occur?

c. +12 kg·m/s -2 kg·m/s -4 kg·m/s +14 kg·m/s

An object on a spring is oscillating in simple harmonic motion. Suddenly friction appears and causes the energy of the system to be dissipated. The system now exhibits ____________.

damped harmonic motion

The moon is 3.85 × 108 m from the earth and has a diameter of 3.48 × 106 m. You have a pea (diameter = 0.50 cm) and a dime (diameter = 1.8 cm). Close one eye and hold each object at arm's length (71 cm) between your open eye and the moon. Which objects, if any, completely cover your view of the moon? Assume that the moon and both objects are sufficiently far from your eye that the given diameters are equal to arc lengths when calculating angles.

dime

A multiple-stage rocket is moving in outer space with a momentum of +150 000 kg·m/s. There are no external forces acting on the rocket. The rocket then separates into two stages, each of which moves along the same direction (either forward or backward) as the initial rocket. The table lists five possibilities for the momenta of the two stages. There is only one possibility that can be correct. Which is it?

e.+250 000 kg·m/s -150 000 kg·m/s

You are in a tall building located near the equator. As you ride an elevator from the ground floor to the top floor, your tangential speed due to the earth's rotation ____________.

increases

Air resistance is a nonconservative force. It always opposes the motion of an object. An airplane flies from New York to Atlanta and then returns to its point of departure. The net work done by air resistance during this round trip ___________.

is negative

A person is riding on a Ferris wheel. When the wheel makes one complete turn, the net work done on the person by the gravitational force ____________.

is zero

An ice skater is spinning on frictionless ice with her arms extended outward. She then pulls her arms in toward her body, reducing her moment of inertia. Her angular momentum is conserved, so as she reduces her moment of inertia, her angular velocity increases and she spins faster. Compared to her initial rotational kinetic energy, her final rotational kinetic energy is _________

larger, because her angular speed is larger.

Two identical satellites are in orbit about the earth. One orbit has a radius r and the other 2r. The centripetal force on the satellite in the larger orbit is __________ as that on the satellite in the smaller orbit.

one fourth as great

Domino Toppling is an event in which a large number of dominoes are lined up close together and then allowed to topple, one after the other. The disturbance that propagates along the line of dominoes is ___________________.

partly transverse and partly longitudinal

Two strings have the same mass and the same length. The tension in string 1 is three times the tension in string 2, however. The speed of a transverse wave on string 1 is ________ times the speed of a transverse wave on string 2.

squareroot 3

A rope is attached to a hook in the ceiling and is hanging straight down. The rope has a mass m, and nothing is attached to the free end of the rope. As a transverse wave travels down the rope from the top, ________________.

the speed of the wave decreases.

The drawing shows a graph of displacement x versus time t for simple harmonic motion of an object on a horizontal spring. Which one of the following answers correctly gives the magnitude v of the velocity and the magnitude a of the acceleration at points A and B in the graph?

vA = maximum, aA = 0 m/s2, vB = 0 m/s, aB = maximum

A stone is thrown with a speed v0 and returns to earth, as the drawing shows. Ignore friction and air resistance, and consider the initial and final locations of the stone. Which one of the following correctly describes the change ΔPE in the gravitational potential energy and the change ΔKE in the kinetic energy of the stone as it moves from its initial to its final location?

ΔPE = 0 J and ΔKE = 0 J

The drawing illustrates an overhead view of a door and its axis of rotation. The axis is perpendicular to the screen. There are four forces acting on the door, and they have the same magnitude. Rank the torque τ that each force produces, largest to smallest.

τ3, τ2, τ1 and τ4 (a two-way tie)