Question

Lee Majors, a professional stuntman, is preparing to run off a dock and dive into a large kayak. The stuntman has a mass of 80.8 kg and the kayak has a mass of 29.9 kg. If Lee dives horizontally with a velocity of 5.50 m/s, what is his velocity immediately after he jumps into the kayak?

Ignore velocities in the y direction.

What I did was (80.8)(v) + 29.9(5.50) = 0 and solved for v. Got -2.04, which was marked incorrect. Where am I going wrong and how do I correct it?

Thank you!

Answer 1

The kayak is initially stationary(V2 = 0). I'm assuming their velocities are equal after landing.

M1*V1 + M2*V2 = M1*V + M2*V.
80.8*5.5 + 29.9*0 = 80.8V + 29.9V.
444.4 = 110.7V,
V = 4.01 m/s.

Answer 2

Thank you!