Bennett Mechanical Test Velocity and Gravity 5

Question 1

Two identical balls are dropped, one from 10 m and one from 20 m. Which hits the ground at a higher speed?

Accepted Answer

The one from 20 m

Answer

A longer fall allows gravity to accelerate the ball for more time, giving a higher impact speed.

Question 2

What is the acceleration of an object at the moment it is released from rest and begins to fall?

Accepted Answer

About 9.8 m/s²

Answer

Gravity acts immediately, so the object accelerates at about 9.8 m/s² from the start.

Question 3

A car going around a circular track at constant speed is accelerating because what is changing?

Accepted Answer

Its direction

Answer

Changing direction changes velocity, which means the car is accelerating even at constant speed.

Question 4

An astronaut on the Moon drops a hammer and a feather together. What happens?

Accepted Answer

They land together

Answer

With no air on the Moon, both fall at the same rate and land together.

Question 5

A ball rolls off a 5 m high table. Roughly how long is it in the air before hitting the floor?

Accepted Answer

About 1 second

Answer

Using t = √(2h/g) = √(10/10) ≈ 1 second.

Bennett Mechanical Test Practice Test