A child leaps on a skateboard: A 35 kg girl is running at a speed of 2.8 m/s when she jumps on a stationary skateboard. If the system consisting of the girl and the skateboard begins rolling at a speed of 2.6 m/s, what is the mass of the skateboard?

Question

anonymous · Answer

use the momentum of conservation formula

anonymous · Answer

M1V1+M2V2=M3V3
M1V1=(M1+M2)V3
IE
35*2.8=(35+x)2.6
x=2.69 kilos

anonymous · Answer

V2=0 since at the beginning the skateboard is at rest

anonymous · Answer

cheers 
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