1. Projectile Review

2. Problem #1
A projectile is launched at an angle of 20 degrees above the horizontal and lands downrange. What other projection angle for the same speed would produce the same downrange distance?
70 degrees

3. Problem #2
What is the name of an object that flies through the air under the influence of gravity? Provide an example.
- The object is called a projectile.
Ex:

4. Problem #3
A rock is thrown upward in the air at a 50 degree angle with respect to the horizontal. As it rises, its horizontal velocity will (speed up, slow down or remain constant)?
remain constant

5. Problem #4
The path that a projectile follows is called what? Draw this path.
Parabolic path

6. Problem #5
When a football is thrown straight upward and it gets to the exact top of its path, describe its vertical velocity and acceleration.
Velocity = 0 m/s
acceleration = 9.8 m/ss.

7. Problem #6
What changes in projectile motion, the vertical or horizontal component of velocity?
The vertical component

8. Problem #7 The velocity of a projectile in the horizontal direction
Is speeding up
Is slowing down
Remains constant

9. Problem #8
If a projectile is fired straight up at a speed of 35 m/s, what is the projectiles speed when it returns to its starting position?
0 m/s
15 m/s
35 m/s
70 m/s

10. At a time before B At a time after B At the same time as B
Problem #9
Sphere A is projected off the edge of a 2.0 m high bench with a horizontal velocity of 4.0 m/s. Sphere B is dropped from the same height as Sphere A. Both spheres have the same size and mass.
If Sphere A leaves the edge of the table at the same instant Sphere B is dropped, Sphere A will land….
At a time before B
At a time after B
At the same time as B

11. Problem #10
Sphere A is projected off the edge of a 2.0 m high bench with a horizontal velocity of 4.0 m/s. Sphere B is dropped from the same height as Sphere A. Both spheres have the same size and mass.
Sphere A’s vertical acceleration at the momentum before it impacts with ground is:
Greater than that of sphere B
The same as that of sphere B
Less that that of sphere B

12. A diver running at 3.6 m/s dives out horizontally from the edge of a cliff and reaches the water below in 2.5 s later.
Calculate:
How high was the cliff?
How far away from the base of the cliff did the diver hit the water?
Gx (Horizontal) U E S
Gy (Vertical)
High cliff = 4.9 x (2.5)2 = 30.3 m Far away? v x t 3.6 m/s x 2.5 = 9 m

13. A diver running at 3.6 m/s dives out horizontally from the edge of a cliff and reaches the water below in 2.5 s later.
Calculate:
How high was the cliff?
How far from the base of the cliff did the diver hit the water?
Gx (Horizontal) U E S
d= 9 m
Gy (Vertical)
h= m

14. 12. A baseball player wishes to determine her pitching speed by throwing a ball horizontally from a height of 4.0 m above the ground. She sees the ball land 25 m down range.
Calculate:
The time it takes the ball to hit the ground.
The horizontally velocity of the ball as it leaves her hand.
Gx (Horizontal) U E S
Gy (Vertical)

15. 12. A baseball player wishes to determine her pitching speed by throwing a ball horizontally from a height of 4.0 m above the ground. She sees the ball land 25 m down range.
Calculate:
The time it takes the ball to hit the ground.
The horizontally velocity of the ball as it leaves her hand.
Gx (Horizontal) U E S
v = 27.7 m/s
Gy (Vertical)
t = 0.90 s

16. 13. A football is thrown with a horizontal velocity of 12
A football is thrown with a horizontal velocity of 12.3 m/s and it hits the ground with a final vertical velocity of 15.5 m/s.
Calculate:
How long was the football in the air for?
How far did the football travel downrange?
How high did the football fall?
Gx (Horizontal) U E S
Gy (Vertical)

17. 13. A football is thrown with a horizontal velocity of 12
A football is thrown with a horizontal velocity of 12.3 m/s and it hits the ground with a final vertical velocity of 15.5 m/s.
Calculate:
How long was the football in the air for?
How far did the football travel downrange?
How high did the football fall?
Gx (Horizontal) U E S
d = m
Gy (Vertical)
h = m
t = 1.58 s