Practice Quiz - Gravity and Acceleration

An airplane that flies at 100 km/h with a 10 km/h tailwind travels at 110 km/h relative to the

ground. If it instead flies into a 10 km/h headwind, its groundspeed is

• 90 km/h

• 100 km/h

• 110 km/h

• 120 km/h

The two measurements necessary for calculating average speed are

• distance and time

• velocity and distance

• velocity and time

• acceleration and time

As an object freely falls downward, its

• acceleration increases

• velocity increases

• both of these

• none of these

Ten seconds after starting from rest, an object falling freely downward will have a speed of about

• 10 m/s

• 50 m/s

• 100 m/s

• more than 100 m/s

A heavy object and a light object are dropped at the same time from rest in a vacuum. The heavier

object reaches the ground

• sooner than the lighter object

• later than the lighter object

• at the same time as the lighter object

If a car increases its velocity from zero to 60 km/h in 10 seconds, its acceleration is

• 3 km/h/s

• 6 km/h/s

• 60 km/h/s

• 10 km/h/s

• 600 km/h/s

A pot falls from a ledge and hits the ground 45 m below. The speed with which it hits the ground is about

• 30 m/s

• 60 m/s

• 120 m/s

• more than 120 m/s