Question

1. Before driving your excellent convertible, you decide to put the top up (made of flexible material).  After merging onto I-64 you bring the car up to the maximum legal highway speed and maintain a steady cruising rate for a time. During this period, with the wind rushing over the top of the car and the air inside the car perfectly still, you notice that the material over the top of the convertible:

		Doesn't do anything in particular.
		Bends slightly inward towards the interior of the car.
		Bends upward and outward.
		Not enough information to know ahead of time.

2. Explain, in words only, the relationship between work and energy. What's the difference between them?

3. An athlete during training exercises his muscles by pressing firmly and steadily against a wall with a force of 500 N for 5.0 minutes. What is the amount of work the athlete does on the wall during this time, in Joules?

Answer 1

2 ) Work is considered if a body gets displaced due to the application of a force. Work done is product of force and displacement of the body in the direction of applied force.

The work done is stored in the form of energy. It might be stored as thermal energy or potential energy or kinetic energy or electrical energy etc. Hence work done is getting converted to energy in various forms.

3). Even though force is applied by the athlete, his displacement is zero . Hence work done by athlete on the wall is zero.