A professional golfer is examining a video of a practice swing. The high‑speed footage shows that his club is in contact with the ball (which was initially at rest on the tee) for only Δ t = 0.771 ms, and the radar gun clocks the speed of the ball as v b = 146 mph after it comes off the club. The golf ball has a mass of m b = 45.9 g. What is the magnitude of the impulse imparted to the ball by the club?

in physics zero. in muscle fatigue could be high

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.