Math/Physics Prep
A running back is running down the (American) football field in a straight line. He starts at the 0-yard line at 0 seconds. At 1 second, he is on the 10-yard line; at 2 seconds, he is on the 20-yard line; at 3 seconds, he is on the 30-yard line; and at 4 seconds, he is on the 40-yard line. What is the player's acceleration?
0 yd/s/s
A circus clown is juggling flaming bowling balls on his unicycle. What is the value of the balls’ accelerations at the peak of their trajectories?
a=g=9.8m/s/s
As an object freely falls, its ...
a.) speed increases.
b.) acceleration increases.
c.) both a and b.
d.) none of the above.
a.) speed increases
A baseball pitcher delivers a fastball. During the throw, the speed of the ball increases from 0.00 m/s to 30.0 m/s over a time of 0.100 seconds. The average acceleration of the baseball is ...
300 m/s/s
In the absence of air resistance, if an object were to fall freely near the surface of the Moon,
a.) it's acceleration would gradually decrease until the object moves with a terminal velocity.
b.) the acceleration is constant.
c.) it will fall with a constant speed.
d.) the acceleration is zero.
b. the acceleration is constant.
When a rock is dropped, it will accelerate downward at a rate of 9.8 m/s/s. If the same rock is thrown downward (instead of being dropped from rest), its acceleration will be ...
9.8 m/s/s
The driver of a car makes an emergency stop by slamming on the car's brakes and skidding to a stop, traveling a distance d. How far would the car have skidded if it had been traveling three times as fast?
9 times as far.
Olympic gold medalist Michael Johnson runs one time around the track – 400 meters – in 38 seconds. What is his displacement? What is his average speed?
displacement = 0 m, average speed = 10.5 m/s (11 m/s with sig figs)
If an object is moving eastward and slowing down, then the direction of its acceleration vector is:
westward.
A ball which is dropped from the top of a building strikes the ground with a speed of 30 m/s. Assume air resistance can be ignored. To the nearest meter, what is the height of the building?
46 meters (45 m is using 10 m/s^2 for g)
Two vectors, one of length 6 and the other of length 8 are added together. What is the range of all possible lengths of the result?
From 2 (could be –2 if considering direction) to 14 meters
A particle continuously moves in a circular path at constant speed in a counterclockwise direction (show image). Consider a time interval during which the particle moves along this circular path from point P to point Q. Point Q is exactly half-way around the circle from Point P.
a.) What is the direction of the average velocity during this time interval?
b.) What is the direction of the average acceleration during this time interval?
a.) to the left
b.) down
A snail is moving along a straight line. Its initial position is xo = –5 meters and it is moving away from the origin and slowing down. In this coordinate system, the signs for the initial position, initial velocity and initial acceleration are ...
initial position = negative, initial velocity = negative and initial acceleration = positive.
An object is released from rest and falls a distance h during the first second of time. In terms of h, how far will it fall during the next second of time?
3h
A whiffle ball is tossed straight up, reaches a highest point, and falls back down. Air resistance is not negligible. Which of the following statements are true?
I. The ball's speed is zero at the highest point.
II. The ball's acceleration is zero at the highest point.
III. The ball takes a longer time to travel up to the highest point than to fall back down.
I only.