APMC physics
The figure above shows two particles, each with a charge of +Q, that are located at the opposite corners of a square of side d. What is the potential energy of a particle of charge +q that is held at point P?
(2/4πE₀)(qQ/d)
As a rocket blasts away from the earth with a cargo for the international space station, which of the following graphs would best represent the gravitational force on the cargo versus distance from the surface of the Earth?
(C)
A 2-kg block slides down a 30° incline as shown above with an acceleration of 2 m/s2. Which of the following diagrams best represents the gravitational force W. the frictional force f, and the normal force N that act on the block?
(D)
A small box of mass m is placed on top of a larger box of mass 2m as shown in the diagram. When a force F is applied to the large box, both boxes accelerate to the right with the same acceleration. If the coefficient of friction between all surfaces is μ, what would be the force accelerating the smaller mass?
(F/3)-mgμ
A block of mass M is initially at rest on a frictionless floor. The block, attached to a massless spring with spring constant k, is initially at its equilibrium position. An arrow with mass m and velocity v is shot into the block. The arrow sticks in the block. What is the maximum compression of the spring?
(mv)/√(m+M)k
A ball is thrown and follows a parabolic path, as shown. Air friction is negligible. Point Q is the highest point on the path. Which of the following best indicates the direction of the net force on the ball at point P ?
*** arrow pointing down
The figure above shows two particles, each with a charge of +Q, that are located at the opposite corners of a square of side d. What is the direction of the net field at point P?
*** arrow pointing down to the left
A rubber ball is held motionless a height ho above a hard floor and released. Assuming that the collision with the floor is elastic, which one of the following graphs best shows the relationship between the total energy E of the ball and its height h above the surface.
*** graph with a straight line
A figure of a dancer on a music box moves counterclockwise at constant speed around the path shown above. The path is such that the lengths of its segments, PQ, QR, RS, and SP, are equal. Arcs QR and SP are semicircles. Which of the following best represents the magnitude of the dancer's acceleration as a function of time t during one trip around the path, beginning at point P ?
*** graph with one closed box and other box open on the right
The parabola on the left is a graph of speed v as a function of time t for an object. Which of the following graphs best represents the magnitude F of the net force exerted on the object as a function of time t?
*** graph with straight line positive
A compressed spring mounted on a disk can project a small ball. When the disk is not rotating, as shown in the top view, the ball moves radially outward. The disk then rotates in a counterclockwise direction as seen from above, and the ball is projected outward at the instant the disk is in the position shown. Which of the following best shows the subsequent path of the ball relative to the ground?
*** inside circle with arrow pointing left arrow outside of circle up and to the right
An automobile moves at constant speed down one hill and up another hill along the smoothly curved surface shown above. Which of the following diagrams best represents the directions of the velocity and the acceleration of the automobile at the instant that it is at the lowest position. as shown?
*** velocity arrow pointing left acceleration arrow pointing up
The graph above represents the potential energy U as a function of displacement x for an object on the end if a spring oscillating in simple harmonic motion with amplitude x₀. Which of the following graphs represents the kinetic energy K of the object as a function of displacement x?
***picture of an upside down parabola
A concave mirror with a radius of curvature of 1.0m is used to collect light from a distant star. The distance between the mirror and the image of the star is most nearly
0.50m
A 5000 kg freight car moving at 4 km/hr collides and couples with an 8000 kg freight car which is initially at rest. The approximate common final speed of these two cars is
1.5 km/h
An object has a weight W when it is on the surface of a planet of radius R. What will be the gravitational force on the object after it has been moved to a distance of 4R from the center of the planet?
1/16W
If the momentum of an electron doubles, its de Broglie wavelength is multiplied by a factor of
1/2
When the frictionless system shown above is accelerated by an applied force of magnitude the tension in the string between the blocks is
1/3 F
Two bodies of masses 5 and 7 kilograms are initially at rest on a horizontal frictionless surface. A light spring is compressed between the bodies, which are held together by a thin thread. After the spring is released by burning through the thread, the 5 kilogram body has a speed of 0.2 m/s. (in m/s)
1/7
Which of the following correctly indicates the magnitudes of the forces acting up and down the incline?
10 N down the plane, 6 N up the plane
Two people are pulling on the ends of a rope. Each person pulls with a force of 100 N. The tension in the rope is:
100N
Two football players with mass 75 kg and 100 kg run directly toward each other with speeds of 6 m/s and 8 m/s respectively. If they grab each other as they collide, the combined speed of the two players just after the collision would be:
2 m/s
Two parallel conducting plates are connected plates are connected to a constant voltage source. The magnitude of the electric field between the plates is 2,000 N/C. If the voltage is doubled and the distance between the plates is reduced to 1/5 the original distance, the magnitude of the new electric field is
20,000 N/C
A negative beta particle and a gamma ray are emitted during the radioactive decay of a nucleus 214Pb. Which of the following is the resulting nucleus?
214 Tl 81
A 2 kg object moves in a circle radius 4 m at a constant speed of 3 m/s. A net force of 4.5 N acts on the object. What is the angular momentum of the object with respect to an axis perpendicular to the circle and through its center?
24 kg m²/s
A diver initially moving horizontally with speed v dives off the edge of a vertical cliff and lands in the water a distance d from the base of the cliff. How far from the base of the cliff would the diver have landed if the diver initially had been moving horizontally with speed 2v?
2d
A tennis ball of mass m rebounds from a racquet with the same speed v as it had initially as shown. The magnitude of the momentum change of the ball is
2mv cos
If photons of light of frequency f have momentum p, photons of light of frequent 2f will have a momentum of
2p
A car of mass m, traveling at speed v, stops in time t when maximum braking force is applied. Assuming the braking force is independent of mass, what time would be required to stop a car of mass 2m traveling at speed
2t
A cart with mass 2m has a velocity v before it strikes another cart of mass 3m at rest. The two carts couple and move off together with a velocity of
2v/5
A physics student places an object 6.0 cm from a converging lens of focal length 9.0cm. What is the magnitude of the magnification of the image produced?
3.0
In a certain process, 400J of heat is added to a system and the system simultaneously does 100 J of work. The change in internal energy of the system is
300 J
An object is released from rest and falls a distance h during the first second of time. How far will it fall during the next second of time?
3h
Mars has a mass 1/10 that of Earth and a diameter 1/2 that of Earth. The acceleration of a falling body near the surface of Mars is most nearly
4 m/s2
The driver of a car makes an emergency stop by slamming on the car's brakes and skidding to a stop. How far would the car have skidded if it had been traveling twice as fast?
4 times as far
A block of mass 3 kg, initially at rest, is pulled along a frictionless, horizontal surface with a force shown as a function of time t by the graph above. The acceleration of the block at t = 2 s is
4/3 m/s²
The electrical resistance of the part of the circuit shown between point X and point Y is
4/3Ω
A person weighing 800 newtons on Earth travels to another planet with twice the mass and twice the radius of Earth. The person's weight on this other planet is most nearly
400N
A ball with a mass of 0.50 kg and a speed of 6 m/s collides perpendicularly with a wall and bounces off with a speed of 4 m/s in the opposite direction. What is the magnitude of the impulse acting on the ball?
5 Ns
At noon a radioactive sample decays at a rate of 4,000 counts per minute. At 12:30 PM the decay rate had decreased to 2,000 counts per minute. The predicted decay rate at 1:30 PM is
500 counts per minute
A student weighing 700N climbs at constant speed to the top of an 8m vertical rope in 10s. The average power expended by the student to overcome gravity is most nearly
560 W
A 50 kg skater at rest on a frictionless rink throws a 2 kg ball, giving the ball a velocity of 10 m/s. Which statement describes the skater's subsequent motion?
6.4 m/s in the opposite direction of the ball's motion
A rectangular wire loop is at rest in a uniform magnetic field B of magnitude 2 T that is directed out of the page. The loop measures 5 cm by 8 cm, and the plan of the loop is perpendicular to the field, as shown above. The total magnetic flux through the loop is
8 X 10⁻¹T-m²
A certain coffeepot draws 4.0 A of current when it is operated on 120 V household lines. If electrical energy costs 10 cents per kilowatt-hour, how much does it cost to operate the coffeepot for 2 hours?
9.6 cents
The graph above shows the decay of a sample of carbon 14 that initially contained N₀ atoms, Which of the lettered points on the time axis could represent the half-life of carbon 14?
A
relate to two objects that start at x = 0 at t = 0 and move in one dimension independently of one another. Graphs, of the velocity of each object versus time are shown below Which object is in its initial position at t=2 seconds?
A
For which of the following motions of an object must the acceleration always be zero?
Any single object in motion with constant momentum
relate to two objects that start at x = 0 at t = 0 and move in one dimension independently of one another. Graphs, of the velocity of each object versus time are shown below Which object is farthest from the origin at t = 2 seconds.
B
A ball falls straight down through the air under the influence of gravity. There is a retarding force F on the ball with magnitude given by F = bv, where v is the speed of the ball and b is a positive constant. The ball reaches a terminal velocity after a time t. The magnitude of the acceleration at time t/2 is
Decreasing
The two spheres pictured have equal densities and are subject only to their mutual gravitational attraction. Which of the following quantities must have the same magnitude for both spheres?
Gravitational force
Quantities that are conserved in all nuclear reactions include which of the following?
I (electric charge)
Units of power include which of the following
I and II only (watt and joule per second)
Three forces act on an object. If the object is in translations equilibrium, which of the following must be true?
I only (the vector sum of the three forces must equal zero)
Which of the following experiments provided evidence that electrons exhibit wave properties?
II only (milkman oil-drop experiment)
One end of a horizontal string is fixed to a wall. A transverse wave pulse is generated at the other end, moves toward the wall as shown above. and is reflected at the wall. Properties of the reflected pulse include which of the following?
III only (it is on the opposite side of the string from the incident pulse)
A certain quantity of an ideal gas initially at temperature T₀, pressure p₀, and volume V₀ is compressed to one-half its initial volume. As shown above the process may be adiabatic (process 1), isothermal (process 2), or isobaric (process 3). Which of the following is true of the final temperature of this gas?
It is greatest for process 1.
A certain quantity of an ideal gas initially at temperature T₀, pressure p₀, and volume V₀ is compressed to one-half its initial volume. As shown above the process may be adiabatic (process 1), isothermal (process 2), or isobaric (process 3). Which of the following is true of the mechanical work done on the gas?
It is greatest for process 1.
Which of the following is true about the net force on an uncharged conducting spare in a uniform electric field?
It is zero
In which of the following situations would an object be accelerated? Select two answers.
It moves with uniform circular motion. It travels as a projectile in a gravitational field with negligible air resistance.
An ice cube of mass m and specific heat c₁ is initially at temperature T₁, where T₁<273 K. If L is the latent heat of fusion of water, and the specific heat of water is c(sub w), how much energy is required to convert the ice cube to water at T₂, where 273 K < T₂ < 373 K?
M[c₁(273-T₁) + L + c(sub w)(T₂-273)]
Each of five satellites makes a circular orbit about an object that is much more massive than any of the satellites. The mass and orbital radius of each satellite are given below. Which satellite has the greatest speed?
Mass Radius m 1⁄2R
Two objects, P and Q, have the same momentum. Q can have more kinetic energy than P if it has:
More speed than P
Multiple correct: If Spacecraft X has twice the mass of Spacecraft Y, then true statements about X and Y include which of the following? Select two answers.
On Earth, X experiences twice the gravitational force that Y experiences. On the Moon, X has twice the weight of Y.
A ball is tossed straight up from the surface of a small, spherical asteroid with no atmosphere. The ball rises to a height equal to the asteroid's radius and then falls straight down toward the surface of the asteroid. What forces, if any, act on the ball while it is on the way up?
Only a decreasing gravitational force that acts downward
Quantum concepts are critical in explaining all of the following EXCEPT
Rutherford's scattering experiments
When light passes from air into water,the frequency of the light remain the same. What happens to the speed and the wavelength of light as it crosses the boundary in going from air into water?
Speed: decreases wavelength: decreases
A ball of mass m is suspended from two strings of unequal length as shown above. The magnitudes of the tensions T1 and T2 in the strings must satisfy which of the following relations?
T1 < T2
A student initially at rest on a frictionless frozen pond throws a 1 kg hammer in one direction. After the throw, the hammer moves off in one direction while the student moves off in the other direction. Which of the following correctly describes the above situation?
The hammer will have great kinetic energy
Multiple Correct: A satellite of mass M moves in a circular orbit of radius R at a constant speed v around the Earth which has mass ME. Which of the following statements must be true? Select two answers:
The net work done on the satellite by gravity in one revolution is zero. The angular momentum of the satellite is a constant
Multiple Correct: Consider two laboratory carts of different masses but identical kinetic energie . Which of the following statements must be correct? Select two answers.
The one with the greatest mass has the greatest momentum Both can do the same amount of work as they come to a stop
A simple pendulum and a mass hanging on a spring both have a period of 1 s when set into small oscillatory motion on Earth. They are taken to Planet X, which has the same diameter as Earth but twice the mass. Which of the following statements is true about the periods of the two objects on Planet X compared to their periods on Earth?
The period of the pendulum is shorter; that of the mass on the spring is the same.
A spring is compressed between two objects with unequal masses, m and M, and held together. The objects are initially at rest on a horizontal frictionless surface. When released, which of the following is true?
The total final momentum of the two objects is zero
Multiple correct: Three forces act on an object. If the object is moving to the right in translational equilibrium, which of the following must be true? Select two answers.
The vector sum of the three forces must equal zero. The object must be moving at a constant speed.
An object is placed at a distance of 1.5f from a converging lens of focal length f, as shown above. What type of image is formed and what is its size relative to the object?
Type: real size: larger
When an object of weight W is suspended from the center of a massless string as shown, the tension at any point in the string is
W/(2cos)
Is it possible for an object's velocity to increase while its acceleration decreases?
Yes, an example would be a falling object in the presence of air resistance
The graph at left shows the relationship between the mass of a number of rubber stoppers and their resulting weight on some far-off planet. The slope of the graph is a representation of the:
acceleration due to gravity
A ball is thrown and follows the parabolic path shown above. Air friction is negligible. Point Q is the highest point on the path. Points P and R are the same height above the ground. Which of the following diagrams best shows the direction of the acceleration of the ball at point P?
arrow facing down
A car is traveling on a road in hilly terrain, see figure to the left. Assume the car has speed v and the tops and bottoms of the hills have radius of curvature R. The driver of the car is most likely to feel weightless:
at the top of a hill when v>√gR
Two toy cars with different masses originally at rest are pushed apart by a spring between them. Which TWO of the following statements would be true?
both toy cars will acquire equal but opposite momenta the more massive toy car will acquire the least speed the smaller toy car will experience an acceleration of the greatest magnitude
An open cart on a level surface is rolling without frictional loss through a vertical downpour of rain, as shown above. As the cart rolls, an appreciable among of rainwater accumulates in the cart. The speed of the cart will
decrease because of conservation of momentum
A ball is tossed straight up from the surface of a small, spherical asteroid with no atmosphere. The ball rises to a height equal to the asteroid's radius and then falls straight down toward the surface of the asteroid. The acceleration of the ball at the top of its path is
equal to one-fourth the acceleration at the surface of the asteroid
A tractor-trailer truck is traveling down the road. The mass of the trailer is 4 times the mass of the tractor. If the tractor accelerates forward, the force that the trailer applies on the tractor is
equal to the force of the tractor on the trailer
Two carts are held together. Cart 1 is more massive than Cart 2. As they are forced apart by a compressed spring between them, which of the following will have the same magnitude for both carts.
force
Starting from rest, object 1 falls freely for 4.0 seconds, and object 2 falls freely for 8.0 seconds. Compared to object 1, object 2 falls:
four times as far
A block of mass 3m can move without friction on a horizontal table. This block is attached to another block of mass m by a cord that passes over a frictionless pulley, as shown above. If the masses of the cord and the pulley are negligible, what is the magnitude of the acceleration of the descending block?
g/4
When there is a steady current in the circuit, the amount of charge passing a point per unit of time is
greater in the 2Ω resistor than in the 3Ω resistor
A plane 5 meters in length is inclined at an angle of 37°, as shown above. A block of weight 20 N is placed at the top of the plane and allowed to slide down. The magnitude of the normal force exerted on the block by the plane is
greater than zero but less than 20 N
A block of weight W is pulled along a horizontal surface at constant speed v by a force F, which acts at an angle of with the horizontal, as shown. The normal force exerted on the block by the surface has magnitude
greater than zero but less than W
A railroad car of mass m is moving at speed v when it collides with a second railroad car of mass M which is at rest. The two cars lock together instantaneously and move along the track. What is the speed of the cars immediately after the collision?
mv/(m+M)
relate to two objects that start at x = 0 at t = 0 and move in one dimension independently of one another. Graphs, of the velocity of each object versus time are shown below Which object moves with constant non-zero acceleration?
neither A nor B
A light ray passes through substances 1, 2, and 3 as shown above. The indices of refraction for these three substances are n₁, n₂, n₃, respectively. Ray segments in 1 and in 3 are parallel. From the directions of the ray, one can conclude that
n₃ must be the same as n₁
A solid metal ball and a hollow plastic ball of the same external radius are released in a large vacuum chamber. When each has fallen 1m, they both have the same
speed
A uniform rope of weight 50 N hangs from a hook as shown above. A box of weight 100 N hangs from the rope. What is the tension in the rope?
t varies from 100 N at the bottom of the rope to 150 N at the top.
A rock is dropped from the top of a tall tower. Half a second later another rock, twice as massive as the first, is dropped. Ignoring air resistance,
the distance between the rocks increases while both are falling.
Quantum transitions that result in the characteristics sharp lines of the X-ray spectrum always involve
the inner electron shells
An electron is in a uniform field B that is directed out of the plane of the page, as shown above. When the electron is moving in the plane of the page in the direction indicated by the arrow, the force on the electron is directed
toward the right
A mass m has speed v. It then collides with a stationary object of mass 2m. If both objects stick together in a perfectly inelastic collision, what is the final speed of the newly formed object?
v/3
A ball is thrown and follows the parabolic path shown above. Air friction is negligible. Point Q is the highest point on the path. Points P and R are the same height above the ground. How do the speeds of the ball at the three points compare?
vQ<vP =vR
A child pushes horizontally on a box of mass m which moves with constant speed v across a horizontal floor. The coefficient of friction between the box and the floor is μ. At what rate does the child do work on the box?
μmgv