Question

A 1250-kg slippery hippo slides down a mud-covered hill inclined at an angle of 18º to the
horizontal. If the coefficient of sliding friction between the hippo and the mud is 0.0900, what
force of friction impedes the hippo’s motion down the hill?

Answer 1

Given the angle of the hill, you can calculate the force applied by the hippo on the surface of the hill

Answer 2

Remember that the normal force of the hippo times the coefficient of sliding friction is equal to the normal force of the hippo, that is the force that the hill applies on the hippo.

Answer 3

I don't remember any equations though or where to plug them in..

Answer 4

Okay. I'm terrible at drawing, so I'll try to do this in words. There are three distinct forces acting on this hippo. One is the force of gravity, pointing straight down, and it is equal to the gravitational constant multiplied by the hippo's mass. The second force is the normal force of the hill on the hippo. This force is perpendicular to the slanted surface. The third force is the force of sliding friction, which is equal to the normal force times the coefficient of sliding friction.