If you slide down a frictionless hill 500 feet long and loses 50 feet in height, half way down what is your speed?

If the above hill has friction, what is the maximum coeffient of static friction so you can start to slide??

use trig to solve for the acceleration down the hill and use one of the 4 kinematic equations to solve for your velocity at the halfway mark (initial velocity=0 distance=250 acceleration=9.8/sinθ)

your max friction will be something like this:
μF(normal)<9.8sinθ, because the acceleration due to gravity down the slope must be greater than the force of static friction for an object to begin sliding