1-Calculate -4 - 3.

2-Calculate 3 - 4 =

3-Calculate 3 - (-4)

4-Okay...one more time... -2 - (-7)

https://www.youtube.com/watch?v=NF8VlIx4Vaw

5-In the slap shot video, and the professor said that the puck experienced "an average force of 100 pounds" which we now know is 445 Newtons of average force. The duration of this collision is .02 seconds. Calculate the Impulse in this puck/stick collision.

6-You calculated the Impulse in Q5. We know that the Impulse also equals the change in momentum. Assuming the puck was at rest before the Julie Chu hit it with her stick, what was the final velocity of the puck after the collision. The initial velocity was 0. The mass of the puck is .175 kg

7-How many miles per hour was the puck going when it left Julie Chu's stick?

https://www.youtube.com/watch?v=-ZLQCsAR_Wk&t=33s

8-According to the Sport Science Video on Serena's serve, how long does it take for the eye to pick up the ball once she hits the serve? Write the time in milliseconds.

9-The opponent to Serena's serve doesn't pick up the ball until it as at the net. How long do they have to react to the serve once it is at this point? Write the answer in milliseconds.

10-Serena's serve is clocked on average at 120 mph. Calculate the impulse (change in momentum) on the ball. Assuming its initial speed is zero m/s and the final speed is 120 mph. Let's change that to m/s. The mass of tennis ball is approximately 0.06 kg.

11-If Serena's racket is in contact with the ball for .005 seconds, what is the average force she hits the ball during her serve? This calculation is in Newtons.

12-What is the acceleration of the tennis ball? In m/s^2