A 30.0 kg seal at an amusement park slides down a ramp into the pool below. The top of the ramp is 1.60 m higher than the surface of the water and the ramp is inclined at an angle of 30.0° above the horizontal. The seal reaches the water with a speed of 4.90 m/s. What is the work is done by kinetic friction? I tried a number of things, but I wasn't sure how to calculate kinetic friction.