A daredevil slides downa ride and the angle he slides is 30º making a 200 meter elevation changes.. Daredevils mass is 60kg. If final velocity is 30m/show much energy was lost due to friction? What is friction force acting during slide and what is the coefficent of friction?

Is the daredevil at rest at the top?

Use the principle of conservation of energy for this.

Potential Energy at top = Kinectic Energy at bottom + Work done due to friction.

Form this, use W = Fd

Find F, the force of friction.

To find the coefficient of friction, use F = μR

R is the normal component of the daredevil and F is the force you found previously.