PHYSICS STUDY GUIDE
a
A 10-kg rock and a 20-kg rock are dropped at the same time and experience no significant air resistance. If the 10-kg rock falls with acceleration a, what is the acceleration of the 20-kg rock?
0 J
A 35-N bucket of water is lifted vertically 3.0 m and then returned to its original position. How much work did gravity do on the bucket during this process?
Its velocity points upward and its acceleration points downward.
A ball is thrown straight up, reaches a maximum height, then falls to its initial height. Which of the following statements about the direction of the velocity and acceleration of the ball as it is going up is correct?
perpendicular to the curve inward
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?
6.7 × 10^7 words
A certain CD-ROM disk can store 600 megabytes of information. If an average word requires 9.0 bytes of storage, how many words can be stored on one disk?
None of the above choices is correct
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
The initial height of the light stone is greater than the initial height of the heavy stone. Just as it reaches the ground, the light stone is traveling faster than the heavy stone. The stones both have the same kinetic energy just as they reach the ground.
A heavy stone and a light stone are released from rest in such away that they both have the same amount of gravitational potential energy just as they are released. Air resistance is negligibly small. Which of the following statements about these stones are correct? (There could be more than one correct choice.)
700 N
A person who normally weighs 700 N is riding in a rather swift elevator that is moving at a constant speed of 9.8 m/s. If this person is standing on a bathroom scale inside the elevator, what would the scale read?
The acceleration is downward at all points in the motion.
A rock from a volcanic eruption is launched straight up into the air with no appreciable air resistance. Which one of the following statements about this rock while it is in the air is correct?
5.0 m/s
A runner runs around a track consisting of two parallel lines 96 m long connected at the ends by two semicircles with a radius of 49 m. She completes one lap in 100 seconds. What is her average speed?
between 7.0 m and 17.0 m
A student adds two displacement vectors that have the magnitudes of 12.0 m and 5.0 m. What is the range of possible answers for the magnitude of the resultant vector?
42 m/s at 31∘ north of west
A velocity vector has components 36 m/s westward and 22 m/s northward. What are the magnitude and direction of this vector?
4.0 s
An airplane increases its speed at the average rate of 15 m/s2. How much time does it take to increase its speed from 100 m/s to 160 m/s?
greater than the weight of the elevator.
An elevator suspended by a vertical cable is moving downward but slowing down. The tension in the cable must be
a straight line making an angle with the time axis.
An object is moving with constant non-zero acceleration in the +x direction. The velocity versus time graph of this object is
a straight line making an angle with the time axis.
An object is moving with constant non-zero velocity in the +x direction. The position versus time graph of this object is
The net force on the object is zero.
An object is moving with constant non-zero velocity. Which of the following statements about it must be true?
is increasing its velocity by 2.0 m/s every second.
An object moving in the +x direction experiences an acceleration of +2.0 m/s2. This means the object
6.45
Given that 1.00 in. = 2.54 cm, how many square centimeters are in 1.00 square inch?
6
How many significant figures are in the number 120.070?
The size of the force is always exactly the same on both of them
If you pound a feather with a hammer, which one feels a greater force?
They hit at the same time.
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
2
In the product A • B • C, A has 5 significant figures, B has 2 significant figures, and C has 3 significant figures. How many significant figures does the product have?
four times Jack's power output.
Jill does twice as much work as Jack does and in half the time. Jill's power output is
four times that of Bill's ball.
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
Both do zero work.
Person X pushes twice as hard against a stationary brick wall as person Y. Which one of the following statements is correct?
exactly g
Suppose a ball is thrown straight up and experiences no appreciable air resistance. What is its acceleration just before it reaches its highest point?
Its acceleration is in the -x direction.
Suppose that a car traveling to the east (+x direction) begins to slow down as it approaches a traffic light. Which statement concerning its acceleration must be correct?
The acceleration is equal to zero.
Suppose that an object is moving with a constant velocity. Which statement concerning its acceleration must be correct?
velocity.
The slope of a position versus time graph gives
acceleration.
The slope of a velocity versus time graph gives
The amount of work done by Joe is equal to the amount of work done by Bob, but the average power exerted by Joe is greater than that of Bob.
Two cyclists who weigh the same and have identical bicycles ride up the same mountain, both starting at the same time. Joe rides straight up the mountain, and Bob rides up the longer road that has a lower grade. Joe gets to the top before Bob. Ignoring friction and wind resistance, which one of the following statements is true?
Neither of them does any work.
Two men, Joel and Jerry, push against a car that has stalled, trying unsuccessfully to get it moving. Jerry stops after 10 min, while Joel is able to push for 5.0 min longer. Compare the work they do on the car.
the friction force from the road
When a car goes around a circular curve on a horizontal road at constant speed, what force causes it to follow the circular path?
-120 m/s 9.8 m/s downward
Which of the following quantities has units of a velocity? (There could be more than one correct choice.)
The horizontal acceleration is always zero and the vertical acceleration is always a non-zero constant downward.
Which of the following statements are true about an object in two-dimensional projectile motion with no air resistance? (There could be more than one correct choice.)
Both of you have the same amount of gravitational potential energy at the top.
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.
slowing down.
You are in a train traveling on a horizontal track and notice that a piece of luggage starts to slide directly toward the front of the train. From this observation, you can conclude that this train is
in a general northwesterly direction.
You are trying to cross a river that flows toward the south with a strong current. You start out in your motorboat on the east bank desiring to reach the west bank directly west from your starting point. You should head your motorboat
It would have skidded 4 times farther.
You slam on the brakes of your car in a panic, and skid a certain distance on a straight level road. If you had been traveling twice as fast, what distance would the car have skidded, under the same conditions?
