College Physics Final concepts
Mel is standing still and watching Alice and Flow move away from him in the same direction. If alice is traveling at 2 m/s relative to Mel and Flo is moving at 1.5 m/s relative to Mel, what is Alice's speed relative to Flo?
+0.5 m/s
A bullet is fired from ground level with a speed of 175 m/s at an angle 30.0 degrees above the horizontal at a location where g = 10.0m/s^2. What is the vertical component of its velocity when it is at the highest point of its trajectory?
0 m/s
A car is traveling along a freeway at 50 mph. What is the linear speed, relative to the highway, at the bottom of the tire?
0 mph
Which two temperature changes are equivalent?
1 C° = 1 K
What is the product of 0.89 and 172.1 using correct significant figures?
150
A truck is towing a car whose mass is one fourth that of the truck. The force exerted by the truck on the car is 16,000 N. The force exerted by the car on the truck is?
16,000 N
0.0002468 can also be expressed as?
2.468 x 10^-4
The temperature in your classroom is closest to
295K
When you drop a pebble from height H, it reaches the ground with speed V if there is no air resistance. From what height should you drop it so it will reach the ground with twice as much kinetic energy?
2H
Two small objects, with masses m and M, are originally a distance r apart, and the gravitational force on each one has magnitude F. The second object has its mass changed to 2M, and the distance is changed to r/4. What is the magnitude of the new gravitational force?
32F
A tiger is running in a straight line. If we double both the mass and speed of the tiger, the magnitude of its momentum will increase by what factor?
4
How many significant figures are in the number 0.001802?
4
When you drop a pebble from height H, it reaches the ground with speed V if there is no air resistance. From what height should you drop it so it will reach the ground with twice speed?
4H
A stretched string is observed to have four equal segments in a standing wave driven at a frequency of 480 Hz. What driving frequency will set up a standing wave with five equal segments?
600 Hz
Two equal-magnitude forces are applied to a door at the doorknob. The first force is applied perpendicular to the door, and the second force is applied at 37 degrees to the plane of the door. Which force exerts the greater torque about the door hinge? a) the first force (applied perpendicular to the door) b) the second force (applied at an angle) c) Both forces exert equal non zero torques d) both forces exert zero torque
A
A satellite is in a circular orbit around Earth. Imagine what would happen if you could turn off gravity. Without gravity, the satellite would now move?
Along a straight-line path in its original direction
A croquet mallet balances when suspended from its center of mass, as shown in the figure (left). If you cut the mallet in two at its center of mass, as shown, how do the masses of the two pieces compare? A) The masses are equal. B) The piece with the head of the mallet has the greater mass. C) The piece with the head of the mallet has the smaller mass. D) It is impossible to tell.
B
A very elastic rubber ball is dropped from a certain height and hits the floor with a downward speed v. Since it is so elastic, the ball bounces back with the same speed v going upward. Which of the following statements about the bounce are correct? a) the ball had the same momentum just before and just after the bounce b) the magnitude of the ball's momentum was the same just before and just after the bounce c) the ball's momentum was conserved during the bounce d) none of the above statements are correct
B
Which of the following is a vector quantity? a) distance b) time c) acceleration d) mass e) temperature
B
Person X pushes twice as hard against a stationary brick wall as person Y. Which one of the following statements is correct?
Both do zero work
You and your friend, who weighs the same as you, want to go to the top of the Eiffel Tower. Your friend takes the elevator straight up. You decide to walk up the spiral stairway, taking longer to do so. Compare the gravitational potential energy of you and your friend, after you both reach the top.
Both of you have the same amount of gravitational potential energy at the top
Pork Chop and Sue E. are riding on a merry-go-round. Sue E. is at a greater distance from the axis of rotation than Pork Chop. Which of the following are true statements? a) Pork Chop has a greater angular speed than Sue E. b) Pork Chop has a smaller angular speed than Sue E. c) Sue E. has a greater tangential speed than Pork Chop d) Pork Chop and Sue E. have the same tangential speed
C
A rock is thrown upwards at an angle of 60 degrees with respect to the horizontal. As the rock is rising in its trajectory, the vertical component of its velocity?
Decreases
When water at 0 degrees Celsius freezes, the entropy of the water
Decreases
You are standing on a skateboard, initially at rest. A friend throws a very heavy ball towards you. You have two choices about what to do with the ball: either catch the ball or deflect it back toward your friend with the same speed as it was originally thrown. Which choice should you make in order to maximize your speed on the skateboard?
Deflect the ball back
A crate is sliding down an inclined ramp at a constant speed of 0.55 m/s. The vector sum of all the forces acting on this crate must point? a) down the ramp b) up the ramp c) perpendicular to the ramp d) vertically downward e) none of the above choices are correct
E
Which one of the following is a true statement? A) The second law of thermodynamics is a consequence of the first law of thermodynamics. B) It is possible for heat to flow spontaneously from a hot body to a cold one or from a cold one to a hot one, depending on whether or not the process is reversible or irreversible. C) It is not possible to convert work entirely into heat. D) It is impossible to transfer heat from a cooler to a hotter body. E) All of these statements are false.
E
A satellite is in orbit around the earth. Which one feels the greater force?
Earth and the satellite feel the same force
In an elastic collision involving and isolated system, the final total momentum is?
Exactly the same as the initial momentum
Two small balls, A and B, attract each other gravitationally with a force of magnitude F. If we now double both masses and the separation of the balls, what will now be the magnitude of the attractive force on each one?
F
A stone is held at a height h above the ground. A second stone with four times the mass of the first one is held at the same height. The gravitational potential energy of the second stone compared to that of the first stone is?
Four times as much
Candace sits on a freely spinning lab stool that has no friction in its axle. When she extends her arms?
Her moment of inertia increases and her angular speed decreases
The intensity of the waves from a point source at a distance d from the source is I. What is the intensity at a distance 2d from the source?
I/4
As a spring is stretch a greater distance the force of the spring on your hand
Increases
If a planet moves with constant speed in a perfectly circular orbit around a star, what is the direction of the acceleration of the planet?
Inward toward the star
When an object moves in uniform circular motion, the direction of its acceleration is?
Is directed toward the center of its circular path
Two wires are made out of the same metal, but one wire is twice as long as the other wire. Which wire will have the greatest elastic modulus?
It will be the same for both wires.
A mass on a spring undergoes SHM. When the mass passes through the equilibrium position, which of the following statements about it are true? (There could be more than one correct choice.)
Its acceleration is zero Its elastic potential energy is zero Its kinetic energy is a maximum
A stone is thrown straight up. When it reaches its highest point,
Its velocity is zero and its acceleration is not zero
When an object is pulled by a force at 24 degrees above the horizontal, how does the norma force compare to the weight of the object?
Less than mg
In the absence of an external force, a moving object will?
Move with a constant velocity
Ferb and Phineas, push against a car that has stalled, trying unsuccessfully to get it moving. Phineas stops after 10 min, while Ferb is able to push for 5.0 min longer. Compare the work they do on the car.
Neither of them does any of work
A batter hits a baseball in a high arc toward center field. At the highest point in its trajectory:
Neither the ball's velocity nor its acceleration is zero
Static equilibrium requires
Net torque and net force are zero
A push of magnitude P acts on a box of weight W as shown in the figure. The push is directed at an angle θ below the horizontal, and the box remains a rest. The box rests on a horizontal surface that has some friction with the box. The friction force on the box due to the floor is equal to
P cos θ
A car goes around a circular curve on a horizontal road at constant speed. What is the direction of the friction force on the car due to the road?
Perpendicular to the curve inward
For general projectile motion, the horizontal component of a projectile's velocity?
Remains a non-zero constant
Two simple pendulums, A and B, are each 3.0 m long, and the period of pendulum A is T. Pendulum A is twice as heavy as pendulum B. What is the period of pendulum B?
T
A 50-kg piece of equipment can be hung by steel wires of length 0.50m, 1.00m, or 3.50m. If all the wires have the same diameter, which one will stretch the greatest distance?
The 3.50m wire
Suppose that an object is moving with a constant velocity. Make a statement concerning its acceleration.
The acceleration must be equal to zero
When a guitar is tuned to adjust it pitch, what is it that is changed?
The frequency of the fundamental
A 5-kg ball collides inelastically head-on with a 10-kg ball, which is initially stationary. Which of the following statements is true? (There could be more than one correct choice.)
The magnitude of the change of velocity the 5-kg ball experiences is greater than that of the 10-kg ball. The magnitude of the change of the momentum of the 5-kg ball is equal to the magnitude of the change of momentum of the 10-kg ball.
A small car meshes with a large truck in head-on collision. Which of the following statements concerning the momentum during the collision are correct?
The momentum of the car-truck system is conserved, but the momentum of each one separately is not conserved
Two objects have masses m and 5m, respectively. They both are placed side by side on a frictionless inclined ramp and allowed to slide down from rest without any air resistance. Which one of the following statements about these objects is correct?
The two objects reach the bottom of the ramp at exactly the same time.
You throw a baseball straight up. Compare the sign of the work done by gravity while the ball goes up with the sign of the work done by gravity while it goes down
The work is negative on the way up and positive on the way down
When a rigid object rotates about a fixed axis, what is true about all the points in the object? (There could be more than one correct choice.)
They all have the same angular speed They all have the same angular acceleration.
Jeremy stands on the edge of a cliff. He throws three identical rocks with the same speed. Rock X is thrown vertically upward, rock Y is thrown horizontally, and rock Z is thrown vertically downward. If the ground at the base of the cliff is level, which rock hits the ground with the greatest speed if there is no air resistance?
They all hit the ground with the same speed
A lightweight object and a very heavy object are sliding with equal speeds along a level frictionless surface. They both slide up the same frictionless hill with no air resistance. Which object rises to a greater height?
They both slide to exactly the same height
Consider the standing wave on a guitar string and the sound wave generated by the string as a result of this vibration. What do these two waves have in common? (There may be more than one correct choice.)
They have the same frequency. They have the same period.
In an air-free chamber, a pebble is thrown horizontally, and at the same instant a second pebble is dropped from the same height. Compare the times of fall of the two pebbles
They hit at the same time
Isabella does the same amount of work as Perry does but in half the time. Isabella's power output is?
Twice Perry's power output
It is more difficult to start moving a heavy carton from rest than it is to keep pushing it with constant velocity, because?
Uk < Us
A brick is stationary on a steep incline. what is the direction of the frictional force?
Up the incline
A push of magnitude P acts on a box of weight W as shown in the figure. The push is directed at an angle θ below the horizontal, and the box remains a rest. The box rests on a horizontal surface that has some friction with the box. The normal force on the box due to the floor is equal to
W + P sin θ.
A car is traveling East and its velocity decreases. The acceleration of the car is in which of the following directions?
Westward
An object is attached to a vertical spring and bobs up and down between points A and B. Where is the object located when its kinetic energy is a minimum?
at either A or B
A large 75-kg lighting fixture can be hung from wires of identical size and shape made of aluminum, brass, or copper. The values of Young's modulus for these metals are 0.70 × 1011 Pa (aluminum), 0.91 × 1011 (brass), and 1.1 × 1011 (copper). Which wire would stretch the least distance?
copper
Joe and Bill throw identical balls vertically upward. Joe throws his ball with an initial speed twice as high as Bill. If there is no air resistance, the maximum height of Joe's ball will be
four times that of Bill's ball
As you are moving very quickly toward a speaker emitting a pure tone, which characteristics of the sound get larger? (There may be more than one correct choice.)
frequency loudness
Two boxes P and Q on a perfectly smooth horizontal surface are connected by a light horizontal cord. The mass of P is greater than that of Q. A horizontal force is applied to box Q as shown in the figure, accelerating the bodies to the right. The magnitude of the force exerted by the connecting cord on body P is
less than F but not zero.
In many cartoon shows, a character runs off a cliff, realizes his predicament, and lets out a scream. He continues to scream as he falls. If the physical situation is portrayed correctly, from the vantage point of an observer at the top of the cliff leaning over the edge, the pitch of the scream as he falls should be
lower than the original pitch and decreasing as he fall
You apply the same force to two objects. Object 1 has mass M and object 2 has mass 5M. The acceleration of object 2 is
one-half as that of object 1
If the units of your answer are kg ∙ m2/s3, which of the following types of quantities could your answer be? (There could be more than one correct choice.)
power
The reason an astronaut in an earth satellite feels weightless is that
the astronaut is falling
A rubber ball and a lump of clay have equal mass. They are thrown with equal speed against a wall. The ball bounces back with nearly the same speed with which it hit. The clay sticks to the wall. Which one of these objects experiences the greater momentum change?
the ball
Two forces produce equal torques on a door about the door hinge. The first force is applied at the midpoint of the door; the second force is applied at the doorknob. Both forces are applied perpendicular to the door. Which force has a greater magnitude?
the first force (at the midpoint)
When a car goes around a circular curve on a horizontal road at constant speed, what force causes it to follow the circular path?
the friction force from the road
Two objects, one of mass m and the other of mass 2m, are dropped from the top of a building. If there is no air resistance, when they hit the ground
the heavier one will have twice the kinetic energy of the lighter one
A rubber ball bounces off of a wall with an initial speed v and reverses its direction so its speed is v right after the bounce. As a result of this bounce, which of the following quantities of the ball are conserved? (There could be more than one correct choice.)
the kinetic energy of the ball
A merry-go-round spins freely when Diego moves quickly to the center along a radius of the merry-goround. As he does this, it is true to say that
the moment of inertia of the system decreases and the angular speed increases
Two boxes, A and B, are connected by a horizontal string S on a horizontal floor. A very light wire pulls horizontally on box B, as shown in the figure, with a force of 100 N. The reaction force to this pull is
the pull of box B on the wire
When a car is weighed, it is driven slowly on a horizontal floor over a scale that records a reading as the front wheels go over the scale, and then records a second reading as the rear wheels go over the scale. The weight of the car is equal to
the sum of the two weights.
Suppose that a sound source is emitting waves uniformly in all directions. If you move to a point twice as far away from the source, the frequency of the sound will be
unchanged
A string of length L is under tension, and the speed of a wave in the string is v. What will be the speed of a wave in the string if the length is increased to 2L but with no change in the mass or tension?
v sq.rt. 2
What is the initial vertical velocity of a projectile with a launch velocity v at an angle (theta) above the horizontal axis?
vcos(theta)
In simple harmonic motion, when is the magnitude of the acceleration the greatest? (There could be more than one correct choice.)
when the magnitude of the displacement is a maximum when the potential energy is a maximum when the kinetic energy is a minimum