Physics Semester Review

a car starts from rest and after 7 seconds it is moving at 42 m/s. what is the car's average acceleration?

• 0.17 m/s2

• 1.67 m/s2

• 6 m/s2

• 7 m/s2

a car accelerates at 2m/s2. assuming the car starts from rest, how much time does it need to accelerate to a speed of 20 m/s?

• 2 seconds

• 10 seconds

• 20 seconds

• 40 seconds

a freely falling object starts from rest. after falling for 1 second, it will have a speed of about

• 5 m/s

• 10 m/s

• 20 m/s

• 40 m/s

if a ball were equipped with a sppedometer and allowed to fall freely on a planet where the acceleration due to gravity is 23 m?s2, the reading of the sppedometer would increase each second by

• 23 m/s

• 12 m/s

• 10 m/s

• a rate that depends on its initial speed

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

• directed downward

• in the direction of motion

• opposite its velocity

• directed upward

a train travels 6 meters in the first second of travel, 6 meters again during the 2nd second of travel, and 6 meters again during the 3rd second. it's acceleration is

• 18 m/s

• 6 m/s

• 0 m/s

• 12 m/s

acceleration is defined by

• the rate at which distance is covered

• the rate at which and object freely falls from the rest

• the rate at which velocity itself changes

• the distance an object has fallen

is a projectile is fired straight up at a speed of 30 m/s, the total time to return to its starting point is about

• 3 seconds

• 6 seconds

• 30 seconds

• 60 seconds

a ball is thrown upwards and caught when it comes back down. in the absence of air resistance, the speed of the ball when caught would be

• less than the speed it had when thrown upwards

• more than the speed it had when thrown upwards

• the same speed it had when thrown upwards

if a freely falling object were somehow equipped with a speedometer, it's speed would increase each second by

• a variable amount

• 10 m/s

• 5 m/s

• 15 m/s