An automobile jack is used to lift a heavy car by exerting a force that is much smaller in magnitude than the weight of the car. Does this mean that less work is done on the car by the force exerted by the jack than if the car had been lifted directly ? Explain.

If you lift a body to aheight h with a force that is equal to the weight of a body,how much work is done and if you lift it with a force that is greater than the weight of a body,where does the extra energy go ?

An automobile sack is lifted by a hydraulic jack that consists of two pistons. The large piston is 1 m in diameter and the small piston is 10 cm in diameter. If W be the weight of the car, how much smaller a force is needed on the small piston to lift the car?

On a railway curve, the outside rail is laid higher than the inside one so that resultant force exerted on the wheels of the rail car by the tops of the rails will

A car is lifted by a hydraulic jack that consists of two pistons. The diameter of the larger piston is 2 m and that of the smaller piston is 50 cm. If the force applied on the smaller piston is 240 N, find the weight of the car.

An automobile back is lifted by a hydraulic jack that consists of two pistons. The large piston is 70 cm in diameter and the small piston is 8 cm in dimater. If W is the weight of the car, how much smaller a force is required on the small piston in order to lift the car ?

When an automobile moves with constant speed down a highway , most of the power developed by the engain is used to compensate on the car by the air and the road, friction forces exerted on the car by the air and the road. If the power developed by an engine is 175 hp , estimate the total friction force (apporox) acting on the car when it is moving at a speed of 25 m//s . One horsepower equals 746 W .

A car weighing 1000 kg and travelling at 30 m//s stops at a distance of 50 m decelerating uniformly. What is the force exerted on it by the breaks ? What is the work done by the brakes?

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 ?