for every 120 joules of energy input a car waste 85 joules, find the useful energy output of the car?

Useful Output = 35 J

Explanation:

The useful energy output of the car must be equal to the difference between the total input energy supplied to the car and the energy wasted by the car:

Useful Output = Total Input - Waste

where,

Total Input = 120 J

Waste = 85 J

Therefore,

Useful Output = 120 J - 85 J

Useful Output = 35 J

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.