1-Using x = v(t), calculate the time it took for the ball to reach you at the plate.

2-For every one foot the catcher is "off", the base the runner gains an advantage of how many feet?

a-3 feet

b-2 feet

c-4 feet

https://www.youtube.com/watch?v=mDBZLdy2K-I

3-Zach Levine's spectacular between the legs slam dunk had a flight time of how long?

a-.92 s

b-.89 s

c-1.01 s

4-In the video they didn't say what Zach Levine's max height was, they did give the length of his horizontal distance. What was that distance?

a-14.8 ft

b-12.1 ft

c-27.6 ft

5-In Aaron Gordon's very entertaining, over the Mascot power slam, what was his hang time?

a.92 s

b.89 s

c.97 s

6-Wait a second, hold on! You mean Gordon had a longer "hang time" than Michael during his iconic 1988 dunk in the NBA slam dunk contest? Yep. How did he do that?

a-He had springs put in his shoes

b-He pushed off the Mascot's head while getting the basketball

c-The guy is just a freak! (Well...maybe...but this isn't the right answer)

7-Aaron Gordon pushed off the ground initially with a force of...

a-1510 lbs

b-1826 lbs

c-1360 lbs

8-Aaron Gordon's center of mass (he balled himself up over the Mascot) was how high off the ground?

a-7 ft 7 in

b-8 ft 9 in

c-5 ft 36 in (hehehe)

9-Elite players make it look like they're "hanging" in the air because....

a-All fans really see are highlight reels which are always done in slo-motion.

b-These athlets actually do "hang" longer than us mere mortals.

c-They elongate their bodies which makes their head glide through a straight horizontal line while their center of gravity is actually falling. This creates the illusion of hangining.

10-If an NBA player came in for a dunk and his center of mass reached it's max height in .42 seconds, how long will it take for his center to go from the max height, back to the starting point?

a-.53 s

b-.42 s

c-.84 s

Time to get "nerdy" with the language here: We have all heard the phrase, "For every action there is an equal and opposite reaction." As I've mentioned before, this is a terrible garbling of Newton's 3rd Law. An interaction between to masses cannot be "equal and opposite". In other words, +2 does not equal -2. But their absolute values (high school algebra term that just made some of you break into a cold sweat and having Math PTSD) are the same. To go way further than we should, absolute value means +2 and -2 are the same distance from 0 on the number line. In physics we say that is the same "magnitude". So Newton's Third Law is actually:

"For every action there is a reaction of equal magnitude in the opposite direction

So far this has been a pretty straightforward, kind of nice and easy lesson. Well just like Ike and Tina, in physics, we "never ever do anything, nice...and eeezzz." We started out nice and easy, just like Pride Mary, but now, it's time to get a little rough. So just like the way Ike and Tina did "Proud Mary," we're going to do "Hang Time!".

So how does one jump? Third Law: Lebron pushes on the Earth and the Earth pushes up on Lebron.

Lebron has a vertical leap of bout 42 inches. This is about average for the NBA. What sets him apart is his speed and reach. But that's for another time. Let's see how we calculate the speed required to get your center of mass to a certain height.

11-Lebron James has a mass of 114 kg and a vertical leap of 42 inches. Convert his vertical leap to meters. It is very close to 1.0 m so carry your calculation out to 4 sigfigs as shown in the picture below. The tolerance on this question is very tight.

To make sure we're all on the same page, let's make sure we get the question above correct. Use 42 inches equals 1.0668 meters.

Use the above number... Cheesy? Yes. But it helps with the rest of the problem.

12-When Lebron is at his highest (42 inbut in meters), what is his Potential Energy? (Hint: mgh)

13-Using the Work Energy Theorem, with what velocity did he take off from the floor? (Hint 1/2mv^2 = mgh Looks like the masses cancel!)

14-If he was in contact with the floor for .05 s and his initial velocity was zero and his final velocity you computed in Q 11, with what force did he push off the floor?

15-With what average acceleration did the floor apply to Lebron to get him up in the air? Remember: F = ma You got the force in problem 12, Lebron's mass is 114 kg, so...

16-Let's check our answer from Q13 using the definition of acceleration. Which is his change in velocity divided by the .05 s the floor was pushing him in the air. (I hope you've seen that number before!)