sorry here is actual question:

Question

A 285-kg stunt boat is driven on the surface of a lake at a constant speed of 13.5 m/s toward a ramp, which is angled at 28.5° above the horizontal. The coefficient of friction between the boat bottom and the ramp's surface is 0.150, and the raised end of the ramp is 1.70 m above the water surface.

a. speed of boat when leaves ramp (engine off once hits ramp)

b. speed of boat when hits water again (no air resistance)

Answer 1

The work-energy theorem
KE2 = KE1 –W(fr) –PE,
KE2 = m•v1²/2 - k•m•g•cosα•s - m•g•h =
= m•v²/2 - m•g•h{(k/tanα) +1} = 2•10^4 J.
KE2 = m•v2²/2,
v2 = sqrt(2•KE2/m) = 11.8 m/s,
The work-kinetic energy theorem for the
boat while it is airborne:
KE3 = ΔPE+KE2 = m•g•h+ m•v2²/2 = 2.46•10^4 J.
KE3 = m•v3²/2,
v3 = sqrt(2•KE3/m) = 13.17 m/s.