Question

Dan is gliding on his skateboard at 2.00 m/s . He suddenly jumps backward off the skateboard, kicking the skateboard forward at 6.00 m/s . Dan's mass is 70.0 kg and the skateboard's mass is 6.00 kg . How fast is Dan going as his feet hit the ground?

Answer 1

Using conservation momentum

MV=m₁v₁+m₂v_{2 .....1}

here M=70+6=76kg, m₁=70kg, m₂=6kg ,v₂=6m/s

put these values in equation ..1

76*2=70v₁ +6*6

v₁=(152-36)/70

=1.66 m/s answer