Skier A of mass 71kg slides down a slope and makes a completely inelastic collision with Skier B, who is stationary, and has a mass of 55kg.Immediately after the collision both skiers have a speed of 5.8m/s.

a)Find the speed of skier A immediately before the collision. (I got this part, 10.3m/s)

b) If skier A slid down the hill with a starting velocity of 0m/s, what is the vertical height of the slope? (I don't get this one, I tried with y=v^2/2g and got 5.4 but its not the right answer)

2 answers

b.

Assuming a) is correct, then
1/2 m vf^2=mgh (ke at bottom=pe at top)

h=1/2 vf^2/g=about 10.3^2 /2*9.8=5.41

I am wondering about significant digits. Your speed after collision is two digits, yet you got correct the part a) with three digits...Then you put in two digits for a)...
I'm guessing the answer sheet has some mistake? It says the height is 9.6m , which I can't seem to figure out how they got that number! :s