       This is the last quiz of Lesson 1: Mechanics.You have studied the relationships between displacement, velocity, acceleration, and time. You also learned what force is, and how it is related to mass and acceleration. You have studied circular and projectile motions as well. Support easyphysics.net by visiting our advertisers' websites. You should have a piece of paper and a pencil with you.

## Chapter 7 Quiz

1. A ball was dropped from a 30 m tall building.

a. What is the acceleration of the ball when t = 1.0?

m/s2

b. What is the velocity of the ball when t = 1.0?

m/s

c. What is the displacement of the ball when t = 1.0?

m

d. How long will it take for the ball to hit the ground?

s

2. A ball was dropped from a helicopter. The helicopter was moving horizontally with a constant velocity of 30 km/h (8.33 m/s) when the ball was released.

a. What is the velocity of the ball on x-direction when t = 2.0, assuming that the ball has not hit the ground yet?

m/s

b. What is the displacement of the ball on x-direction when t = 2.0, assuming that the ball has not hit the ground yet?

m

c. What is the velocity of the ball when t = 2.0, assuming that the ball has not hit the ground yet?

m/s

d. The ball hit the ground when t = 3.2. What was the height of the helicopter when the ball was dropped?

m

e. If the height of the helicopter was 160 m, how long will it take for the ball to hit the ground?

s

3. Mike threw a baseball with an initial velocity of 80 km/h (22.22 m/s) with an angle of 30 degrees. Assume that the ball was released at the height of 1 m. a. What is the velocity of the ball on x direction when the ball was released?

m/s

b. What is the velocity of the ball on y direction when the ball was released?

m/s

c. How long will it take for the ball to hit the ground?

s

d. How far has the ball traveled when it hit the ground?

m