A crate of 20.0 kg slid down a 3.00 m long ramp inclined at 30.0° to the horizontal.
i) Compute the speed of crate at the bottom of the ramp when the ramp is frictionless.
ii) Compute the work done by friction (a non-conservative force) when the speed of crate at the bottom of the ramp is 4.75 m/s.