Posted by **KRIS** on Friday, March 16, 2012 at 12:29am.

A roller coaster reaches the top of the steepest hill with a speed of 3.0 km/h . It then descends the hill, which is at an average angle of 40 degrees and is 50.0 m long. Estimate its speed when it reaches the bottom. Assume kinetic friction (uk) = 0.18.