- #1

BioBabe91

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## Homework Statement

A skier of mass 55.0 kg slides down a slope 11.7 m long, inclined at an angle θ to the horizontal. The magnitude of kinetic friction is 41.5 N. The skier's initial speed is 65.7 cm/s (0.657 m/s) and the speed at the bottom of the slope is 7.19 m/s. Determine the angle θ from the law of conservation of energy. Air resistance does not matter.

## Homework Equations

Ek = 1/2*m*v^2

Eg = mgh

Ethermal = W = Fk*cosθ*Δd

## The Attempt at a Solution

Eth= Fk*cosθ*Δd

Substituted in the values, then used conserv. of energy:

mgh + 1/2*mv^2 = 1/2*mv^2 + Eth

where h = 11.7/sinθ.

But I got stuck solving for the angle. Where did I go wrong?