A 2000kg car starts from rest at point A on a 6 degree incline and coasts through a distance of 150m to point B. The brakes are then applied, causing the car to come to a complete stop at point C, 20m from B. Knowing that slipping is impending during the breaking period and neglecting air resistance and rolling resistance, determine (a) The speed of the car at point B, (b) the coefficient of static friction between the tires and the road.

a) 17.53 m/s

b) 0.788

Explanation:

Let g = 9.8 m/s2. This gravitational acceleration can be split into 2 components, 1 parallel and the other perpendicular to the incline

The parallel component:

We can use the following equation of motion to find the velocity at point B, knowing that it starts from rest at point A and coast through a distance of s = 150 m at rate of 1.024 m/s2

b) we can apply the same formula to find out the deceleration from B to C, knowing that it comes to a stop at C after S = 20m

Using Newton's 2nd law we can find the friction force

Which consists of normal force N and coefficient of static friction

the doppler effect is used by weather forecasters to measure 

moving clouds