How fast is Dan going as his feet hit the ground Dan is glid

How fast is Dan going as his feet hit the ground?

Dan is gliding on his skateboard at 3.00 m/s. He suddenly jumps backward off the skateboard, kicking the skateboard forward at 7.00 m/s (as measured by an observer on the ground). Dan\'s mass is 70.0 kg and the skateboard\'s mass is 4.00 kg. You may want to review For help with math skills, you may want to review: Solving Algebraic Equations For general problem-solving tips and strategies for this topic, you may want to view a Video Tutor Solution of Softball toss

Solution

From law of momentum conservation

P_initial = P_final

(M + m) * u = m * v₁ + M * v₂

(70 + 4) * 3 = 4 * 7 + 70 * v₂

222 = 28 + 70 * v₂

v₂ = 2.77 m/s