physics
posted by bola .
Assume the height of a hill is 50m, calculate:
a.the velocity of a car at the bottom ofg the hill
b.the height at which it will have half the speed. Assume the car starts from rest at the top of the hill.

You can only make this calculation if you assume that the car is "coasting" in neutral with zero friction. These are rather unrealistic assumptions for driving a car.
I suggest you make these assumptions anyway use conservation of energy to predict the speeds. 
A hill is of height 50 meters calculate (a)the velocity of the car at the bottom of the hill.(2)the height at which it will have half d speed.Assume the car starts from rest at the top of the hill