# Chapter-3 Falling Objects and Projectile Motion ## Projectile Motion:

A Cartoon Coyote Falling off a Cliff

### Horizontal and Vertical motions

Q: What determines the time of flight?

A: Vertical motion

### Problems

v

 v

0

 at d

 v

0 t

1

2 at

2 d

1

2

( v

 v

0

) t

Acceleration due to gravity = 10 m/s 2 v

2

 v

0

2 

1. A penny is dropped with zero velocity from the top of a 150 m building. What will be the velocity as it reaches the ground?

2. A ball is thrown straight upward with an initial velocity of 25 m/s.

a. What is the velocity at the high point in its motion?

b. How much time it takes to reach the high point?

c. How high is the high point?

d. What is the velocity of the ball 3 seconds after its throw?

3. A pitcher throws a baseball at a speed of 90 MPH, horizontally. The pitcher’s mound is

60 ft from home plate.

a. What is the speed in m/s?

b. What is the distance to home plate in meters?

c. How much time is required for the ball to reach home plate?

d. How far does the ball vertically drop during the throw?