1. August 29
AP physics

2. In:
A stone is thrown horizontally with an initial speed of 10 m/s from a bridge. If air resistance could be ignored, how long would it take the stone to strike the water 80 m below the bridge?
1 s
2 s
4 s
6 s
8 s

3. Objective:
To use 2 dimensions to understand projectile motion.

4. Homework check

5. Projectile motion

7. Horizontal and Vertical directions are independent.

8. Horizontal motion has constant velocity.

9. Vertical motion is freefall motion.

10. Divide and conquer!
Horizontal Vertical
Time crosses the line!

11. Practice:
A ball is kicked with a velocity of 20 m/s at an angle of 45o from horizontal.
What is the horizontal and vertical initial velocity?

12. How high will it go?

13. How far will it go?

14. A cannon shoots a cannon ball at 18m/s at an angle of 30o from the horizontal. What is the distance the cannonball goes?

16. Wiley Coyote slides horizontally off a 100 m cliff at 75 m/s
Wiley Coyote slides horizontally off a 100 m cliff at 75 m/s. How far from the base of the cliff will he land?

18. A bullet shoots from a gun at 200 m/s at an angle of 55o from the horizontal. How long is it in the air? How high will the bullet go? How far will the bullet travel.

20. A man jumps from a burning building 30 meters from the ground
A man jumps from a burning building 30 meters from the ground. His initial velocity is 10 m/s at 25o from the vertical. How long did it take him to land? How far away from the building should the firemen hold the net?

22. A tennis player hits a ball from 10 meters away from the net that just barely clears the .75 meter net. His initial velocity was 20 m/s. What was the angle he hit it with?

24. Projectile motion
Horizontal Vertical

26. A diver jumps off the 10 meter platform with a velocity of 8 m/s at an angle of 55o from the horizontal. What were the horizontal and vertical components of her jump. How long does it take her to hit the water?

28. Out:
A stone is thrown horizontally with an initial speed of 30 m/s from a bridge. Find the stone’s total speed when it enters the water 4 seconds later.
30 m/s
40 m/s
50 m/s
60 m/s
70 m/s