I'm sorry if this is the wrong place to post, but I am in urgent need of some physics help. Hopefully there are physicists in this forum that can help me out. Any help would be much appreciated!

1) Two football players of masses m and M are involved in an inelastic collision. The inital veloctities of the two players are 7.2m/s [E20N] and 8.1m/s [N30E] respectively. The heavier player moves Northeast after the collision. What is the mathematical relationship between the two massses?

2) A tennis racquet hits a ball initially moving at 52m/s [S70E]. Following the impact, the ball changes its direction, but not its speed. The new direction is [N70E]. If the two objects were in contact for 2*10^^{-3} seconds, and the mass of the ball is 180grams, what was impulse imparted on the ball?

Guest Jan 21, 2018

#1**+2 **

Looked up a few things about INelastic collisions and found this webpage which may be what you are looking for in your first question: (?)

http://hyperphysics.phy-astr.gsu.edu/hbase/inecol.html

where m1 and m2 can be m and M in your question....

ElectricPavlov
Jan 21, 2018

#2**+2 **

I'll take a **SHOT** at the second question as follows..... (I'm going into things I have not seen for > 30 years...I could be quite INCORRRECT):

J= impulse = F(t2-t1) = mv2-mv1 = m (v2-v1) (1) (hmmmm ...doesn't appear I need the time of contact involved)

m = 180 grams

v2 = 52 sin70 + 52 cos 70

v1 = -52 sin70 + 52 cos 70

so v2-v1 = 52sin70 + 52cos70 - (-52sin70 + 52 cos 70)

= 104 sin70 = 97.728 m/s

then from (1) above 180 gm (97.728 m/s) = 17591 gm - m/s = 17.591 kg - m/s =17.591 N*s

(This assumes I understand the notation for direction (S70E etc) used in your question! to look something like this: )

ElectricPavlov
Jan 21, 2018