PHYS Ch 3 Quiz 1

Which of the following best describes acceleration?

• Change in velocity over time

• Distance traveled over time

• Change in position over time

• The force applied to an object

A car is moving north at 20 m/s and then turns east at 20 m/s. What happens to the acceleration?

• There is no acceleration because speed is constant

• There is acceleration because velocity changes direction

• Acceleration only occurs when speed increases

• Acceleration only occurs when speed decreases

If an object has positive velocity and positive acceleration, what is happening?

• The object is moving at a constant speed

• The object is at rest and will remain at rest

• The object is speeding up

• The object is slowing down

When both acceleration is positive and velocity is negative, what does that mean?

• The object is speeding up

• The object is slowing down

• The object is moving at constant speed

• The object has stopped

A car accelerates from rest at 2.0 m/s². How fast is it moving after 5.0 s?

• 5.0 m/s

• 10 m/s

• 15 m/s

• 20 m/s

A ball is dropped from rest and accelerates at 9.8 m/s². How far does it fall in 3.0 s?

• 14.7 m

• 29.4 m

• 44.1 m

• 88.2 m

You jump off of a high dive. If you took 0.78 seconds to hit the water, and your acceleration was
9.8 m/s², how high was the jump?

• 2.98 m

• 0.76 m

• 4.21 m

• 1.63 m

A car traveling at 25 m/s comes to a stop in 5.0 s. What is the acceleration?

• –2.5 m/s²

• –5.0 m/s²

• –10 m/s²

• –25 m/s²

A rocket starts from rest and accelerates at 4.0 m/s/s. How far has it traveled after 8.0 s?

• 64 m

• 96 m

• 128 m

• 256 m

You drop a ball from a height of 3.6 m. If the ball accelerates at 9.8 m/s², what is it's velocity just before it hits the ground?

• 8.4 m/s

• 2.7 m/s

• 5.9 m/s

• 6.8 m/s