Solve Momentum Problem for Dan on Skateboard

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The discussion revolves around solving a momentum problem involving Dan on a skateboard. The key equation provided relates the final velocity of Dan after he jumps off the skateboard, incorporating both his mass and the skateboard's mass. Dan's initial speed is 3.00 m/s, and after jumping backward, he kicks the skateboard forward at 8.00 m/s. Participants emphasize understanding the underlying concepts of momentum rather than focusing solely on memorizing equations. The goal is to determine Dan's speed as he lands on the ground after the jump.
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This is an equation I found in the achieve can anyone explain what this means
||\vec{v}_{f}||=\frac{1}{m_{1}+m_{2}}\sqrt{(m_{1}v_{1}-m_{2}v_{2}\cos(30))^{2}+m_{2}^{2}v_{2}^{2}\sin^{2}(30)}
here is the problem Dan is gliding on his skateboard at 3.00 m/s. He suddenly jumps backward off the skateboard, kicking the skateboard forward at 8.00 m/s (as measured by an observer on the ground). Dan's mass is 40.0 kg and the skateboard's mass is 5.00 kg. How fast is Dan going as his feet hit the ground?
I am just not sure which equation to use.
 
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Forget equations, they're hard to memorise in the first place :rolleyes:. Instead, think about the concepts involved. Which concept(s) do you think are important here?
 
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