- #1
rpullo
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Homework Statement
"Rockey Bourchard" sends a 0.4 kg puck at 80 m/s which is caught by goalie "Crazy Chretien" who is stationary on his knees on the ice. If the coefficient of friction of Chretien on the ice is 0.05, and his total mass is 90 kg, how far does he slide on the ice before coming to a stop?
Homework Equations
mv = mv' (conservation of momentum)
W = (delta)Ek
The Attempt at a Solution
Alright guys, I was just wondering if you can confirm this as the proper solution.
So first I found the momentum of the puck:
p = mv = (0.4kg)(80m/s) = 32 kg m/s
Since momentum is conserved, we can find the speed of the puck as it hits Chretien
v = p'/m = (32 kg m/s)/(90 kg) = 0.3556 m/s
With the equation "W = (delta)Ek"
I change it to " -F * d = 0.5mv2^2 - 0.5 m v1^2 "
and since v2 = 0 and the -F * d becomes ' μmgd', I got the equation
-μmgd = -0.5mv1^2
Solve for d:
d = (v1^2)/(2μg) = (0.3556 m/s)^2/(2*0.05*9.8m/s^2) = 0.13 m