Brakes are suddenly applied to a speeding car and it comes to a. screeching halt. Is the sound energy produced in this conversion a useful form of energy? Explain your answer.

What form of energy do you use to produce sound ?

Can any source of energy be pollution free ? Explain your answer with an example.

The brakes of a car moving at 20 m/s along a horizontal road are suddenly applied and it comes to rest after travelling some distance if the coefficient of friction between the tyres and the road is 0.90 and it is assumed that all four tyres behave identically, the shortest distance the car would travel before coming to a stop is

A girl is sitting in the middle of a park of dimension 12 m xx 12 m . On the left side of it there is a building adjoining the park and on right side of the park, there is a road adjoining the park. A sound is produced on the road by a cracker. Is it possible for the girl to hear the echo of this sound ? Explain your answer.