1. Mike Wilson holds the world record for the highest slam dunk
Mike Wilson holds the world record for the highest slam dunk. This picture shows him setting the record by dunking on a 12 ft. goal.
What is Mike Wilson’s speed at the top of his jump?
What is his acceleration immediately after his feet leave the floor
What is his acceleration at the top of his jump?

2. 1-D Projectile Motion

3. Look Familiar?

4. Is the ball’s velocity constant as it falls?

5. No, It changes by 10 m/s every second
Is the ball’s velocity constant as it falls?
No, It changes by 10 m/s every second

6. is the acceleration constant?
So…...
is the acceleration constant?

7. Yeah …
a = -10 m/s2 the whole time

8. Sample Problem
A 3-kg watermelon is thrown upward from the ground with an initial velocity of 30 m/s.
How much time will it take to reach its highest point?
What will be the velocity of the watermelon when it has been in the air for 4 seconds?
How much time will it take to land?
What will be the velocity of the watermelon when it lands?

9. More Sample Problems
A 3-kg watermelon is thrown upward from the ground with an initial velocity of 30 m/s. (SAME SCENARIO AS BEFORE)
After being in the air for one second, how far above the ground is the watermelon?
When the watermelon reaches its apex, how high will it be above the ground?
How high above the ground will the watermelon be when it has been in the air for four seconds?
By the time the watermelon come back down to the ground, it will have traveled a total distance of m.

10. What if the object doesn’t start from rest?
Sometimes an object will have an velocity (vi); it is thrown up or down
Once the object has been thrown, the force of is the on the object’s vertical motion (we’ll assume no horizontal motion-this will come later)
If we air resistance, acceleration due to gravity is constant
To be consistent, we will treat gravity (g) as a value

11. Calculating when an initial velocity is involved
The velocity of an object at a given moment can be determined using the following:
(vf = vi + at) a=g = -10 m/s2
The distance an object travels at any moment during its flight can be determine using the following: (d= vit + ½ at2)
Vi is if the object is thrown down
Vi is if the object is thrown up

12. Questions when there is a Vi
What happens to the velocity of an object as it is moving upward?
What happens to the velocity of an object as it is moving downward?
What is the velocity of an object when it reaches its highest point?
Does gravity still act on the object when it reaches its highest point?
What would be the acceleration of the object at its highest point?