pls try giving a answer.?
A football of mass 0.42kg is thrown at a stationary student of mass 50.0kg who is wearing roller blades as shown below. When she catches the ball she moves to the right.
The instantaneous speed after she catches the ball is 0.10ms1. Calculate the speed of the ball just before it is caught.

answers:
oubaas say: Conservation of momentum shall apply :
Vb = V*(mb+ms)/mb = 0.10*(50+0.42)/0.42 = 12.00 m/sec

say: v is initial velocity of ball.
Its initial momentum = mass x velocity = 0.42v
After catching then ball, mass of student+ball = 50.42kg.
Final momentum = mass x velocity = 50.42 x 0.10 = 5.042
Initial momentum = final momentum
0.42v = 5.042
v = 5.042/0.42 = 12m/s

billrussell42 say: "as shown below" ??
but I think you can use conservation of momentum.
0.42V = 50•0.1
V = 5/0.42 m/s (about 12 m/s)

moveen say: any help
