5. In a typical golf swing the club is in contact with the ball for about 0.0010 s. If the 45-g ball acquires a speed of 67 m/s, estimate the magnitude of the force exerted by the club on the ball.

A) 3.0 x N

B) 2.9 x N

C) 2.3 x N

D) 1.7 x N

In step 3, I do not understand where the (6e-3)^2 comesfrom.

I do not understand how to find the Umax when i'm giving that my Us is 4.06.

I cannot understand where my teacher keeps getting these gigantic formulas for ΔF, ΔU, and ΔK. I get ΔF more than the other two by far, but I still do not really get it very well. The other two I do not understand at all. If someone could generally explain where these formulas come from i would really appreciate it.