Physics: Chapter 4

A free falling object starts from rest. After falling for 6 seconds, it will have a speed of about a. 6m/s b. 30m/s c. 60m/s d. 300 m/s e. more than 300 m/s

c. 60m/s

A ball is thrown straight up. At the top of its path its acceleration is a. 0 m/s^2 b. about 5 m/s^2 c. about 10 m/s^2 d. about 20 m/s^2 e. about 50 m/s^2

c. about 10 m/s^2

When something falls to the ground, it accelerates. This acceleration is called the acceleration due to gravity and is symbolized by the letter g. What is the value of g on Earth's surface? a. 0 m/s^2 b. about 5 m/s^2 c. about 10 m/s^2 d. about 20 m/s^2 e. about 50 m/s^2

c. about 10 m/s^2

Acceleration is defined as a. the rate at which distance is covered b. the rate at which an object freely falls from rest c. the rate at which velocity itself changes d. the distance an object has fallen

c. the rate at which velocity itself changes

A ball tossed vertically upward rises, reaches its highest point, and then falls back to its starting point. During this time the acceleration of the ball is always A. in the direction of motion B. opposite its velocity C. directed downward D. directed upward

C. directed downward

When you look at the speedometer in a moving car, you can see the car's A. average distance traveled. B. instantaneous acceleration. C. average speed. D. instantaneous speed. E. average acceleration

D. instantaneous speed.

A ball is thrown straight up. At the top of its path its instantaneous speed is a. 0 m/s^2 b. about 5 m/s^2 c. about 10 m/s^2 d. about 20 m/s^2 e. about 50 m/s^2

a. 0 m/s^2

Suppose you take a trip that covers 180 km and takes 3 hours to make. Your average speed is A. 30 km/h. B. 60 km/h. C. 180 km/h. D. 360 km/h. E. 540 km/h.

B. 60 km/h.

Suppose an object is in free fall. Each second the object A. The same distance as in the second before B. a larger distance than in the second before. C. With the same instantaneous speed D. With the same average speed

B. a larger distance than in the second before.

A car starts from rest and after 7 seconds it is moving at 42 m/s. what is the car's average acceleration? A. .17 m/s^2 B. 1.67m/s^2 C. 6m/s^2 D. 7m/s^2

C. 6m/s^2

In the absence of air resistance, objects fall at constant A. Speed B. velocity C. Acceleration D. Distance each successive second

C. Acceleration

Suppose you are in a car that is going around a curve. The speedometer reads a constant 30 miles per hour. Which of the following is not true? A. You and the car are accelerating. B. your acceleration is constantly changing. C. Your velocity is constant D. Your direction is constantly changing E. your speed is constant

C. Your velocity is constant

Suppose a car is moving in a straight line and steadily increases its speed. It moves from 35 km/h to 40 km/h the first second and 40 km/h to 45 km/h the next second. What is the car's acceleration?

5 km/h/s

A train travels 6 meters in the first second of travel, 6 meters again during the second second of travel, and 6 meters again during the third second. Its acceleration is A. 0 m/s^2 B. 6 m/s^2 C. 12 m/s^2 D. 18 m/s^2

A. 0 m/s^2

A car accelerates at 2 m/s^2. Assuming the car starts from rest, how much time does it need to accelerate to a speed of 20m/s? A. 2 sec B. 10 sec C. 20 sec D. 40 sec

B. 10 sec

Acceleration is defined as the CHANGE in A. Time it takes to move from one place to another place B. velocity of an object C. Distance divided by the time interval D. Velocity divided by the time interval E. time it takes to move from one speed to another speed

D. Velocity divided by the time interval

The hang time (time one's feet are off the ground in a jump) for most athletes is a. less than 1 second b. considerably more than 1 second c. about one second d. slightly more than one second

a. less than 1 second

If a projectile is fired straight up at a speed of 30 m/s, the total tim to return to its starting point is about a. 3 seconds b. 6 seconds c. 30 sec. d. 60 sec.

b. 6 seconds

If free falling object were somehow equipped with a speedometer, its speed reading would increase each second by a. about 5 m/s^2 b. about 10 m/s^2 c. about 15 m/s^2 d. a variable amount e. a rate that depends on its initial speed

b. about 10 m/s^2

A free falling object starts from rest. After falling for 1 seconds, it will have a speed of about a. 5m/s b. 10m/s c. 20m/s d. 40m/s

b.10m/s

The vertical height attained by a basketball player who achieves a hang time of a full one second is about a. 0.8 m. b. 1m c. 1.2m d. 2.5m e. more than 2.5m

c. 1.2m

If a ball were equipped with a speedometer and allowed to fall freely on a planet where the acceleration due to gravity is 23 m/s^2, the reading on the speedometer would increase each second by a. a rate that depends on its initial speed b. 10 m/s c. 12 m/s d. 23 m/s e. 46 m/s

d. 23 m/s

Suppose a jumper claims a hang time of 2 seconds. Then that jumper must be able to jump a vertical distance of a. 1m b. 2m c. 3m d. 4m e. 5m

e. 5m

When a basketball player jumps to make a shot, once the feet are off the floor, the jumper's acceleration a. varies with body orientation b. depends on launch speed c. is usually greater for taller players, but not always d. depends on all of the above e. is g; no more, no less

e. is g; no more, no less