Question

Olaf is standing on a sheet of ice that covers the football stadium parking lot;there is negligible friction between his feet and the ice. A friend throws Olaf a ball of mass 0.400kg that is traveling horizontally at 10.6m/s . Olaf's mass is 67.3kg . (a)If Olaf catches the ball, with what speed (Vf) do Olaf and the ball move?afterward? b)If the ball hits Olaf and bounces off his chest horizontally at 8.70 m/s in the opposite direction, what is his speed after the collision?

Answer 1

A) I got the answer for part A right which was .063m/s. For part b I did (.4kg)(10.6m/s)+(67.3)(0)=(.4kg)(-8.7m/s)+(67.3kg)(Vf)

I solved for Vf and i got 1.12m/s But the answer was not right. I also tried -.0112m/s to see if I got the units wrong but that still did not work! Please help me find my mistake I only have two attempts left to get the answer right! :(

Answer 2

did you try .112? (The answer has to be positive.)

Answer 3

I put a positive number before it was not .112 but there was a side note that said that momentum was a vector quantity. Do I put .112? or .0112?

Answer 4

You've set everything up correctly, I think you just made an algebra mistake. (Olaf has to move in the same direction as he did in part a)

Answer 5

So would I round to .0112 or .112? :O I am not sure what is right and I only have two attempts left D: Thank you so much for your help by the way!!

Answer 6

When I did it I got vf = (0.4 kg)(10.6 + 8.7) m/s / 67.3 kg = .1147 m/s, so I'd round to
.115

Answer 7

Oh! I see! I did make an algebra mistake :/ :O I ended up getting the same just now and the answer ended up being right! Thanks so much!