Why do the brake drums of a car get heated, when the car moves down a hill at a constant speed?

The period of a simple pendulum suspended from the ceiling of a car is T when the car is at rest. If the car moves with a constant acceleration the period of the pendulum

A car travels up a hill at a constant speed of 35 km/h and returns down the hill at a constant speed of 60 km/h. Calculate the average speed for the round trip.

A car of mass m 1600 kg, while moving on any road, experience resistance to its motion given by (m+nV^(2)) newton, where m and n are positive constants. On a horizontal road the car moved at a constant speed of 40 m/s when the engine developed a power of 53 KW. When the engine developed an output of 2 KW the car was able to travel on a horizontal road at a constant speed of 10 m/s. (a) Find the power that the engine must deliver for the car to travel at a constant speed of 40 m/s on a horizontal road. (b) The car is able to climb a hill at a constant speed of 40 m/s with its engine working at a constant rate of 69 KW. Calculate the inclination of the hill (in degree)

A boy projects a stone vertically perpendicular to the trolley car with a speed v. If the trolley car moves with a constant velocity u, the time of flight of the stone is :

A 1900-kg car experiences a combined force of air resistance and friction that has the same magnitude whether the car goes up or down a hill at 27 m/s. Going up a hill, the car's engine needs to produce 47 hp more power to sustain the constant velocity than it does going down the same hill. At what angle is the hill inclined above the horizontal ?

Car A and car B start moving simultaneously in the same direction along the line joining them. Car A moves with a constant acceleration a=4 m//s^2, while car B moves with a constant velocity v=1 m//s. At time t=0, car A is 10 m behind car B. Find the time when car A overtake car B.

Why do tyres of cars wear out gradually ?