In one of the exercises to strengthen the wrist and fingers, a person squeezes and releaases a soft rubber ball. Is the work done on the ball positive, negative or zero during compression? During expansion?

Is work done during expansion is positive or negative ?

Find whether work is positive, negative or Zero. Person completing one circle and returns to position A

Work done during expansion is positive. Explain.

These questions consists of two statements each printed as Assertion and Reason. While answering these question you are required to choose any one of the following five reponses (a) If both Assertion and Reason arecorrect and Reason is the correct explanation of Asserrtion. (b) If both Assertion and Reason are correct but Reason is not the correct explanation of Assertion. (c ) If Assertion is true but Reason is false. (d) If Assertion is false but Reason is true. Assertion Total work done by spring may be positive ,negative or zero. Reason Direction of spring force is always towards mean position.

These questions consists of two statements each printed as Assertion and Reason. While answering these question you are required to choose any one of the following five reponses (a) If both Assertion and Reason arecorrect and Reason is the correct explanation of Asserrtion. (b) If both Assertion and Reason are correct but Reason is not the correct explanation of Assertion. (c ) If Assertion is true but Reason is false. (d) If Assertion is false but Reason is true. Assertion Total work done by spring may be positive ,negative or zero. Reason Direction of spring force is always towards mean position.

A body of mass m is attached to the spring which is elongated to 25 cm by an applied for from its equilibrium position, (a) Calculate the potential energy stored in the spring-mass system? (b) What is the work done by the spring force in this elongation? (C) Suppose the spring is compressed to the same 25 cm, calculate the potential energy stored and also the work done by the spring force during compression. (The spring constant, k=0.1Nm^(-1)) .

During isothermal expansion at 800 K, the working substance of a Carnot's engine extracts 480 cal of heat. If the sink be at 300 K, calculate (i) the work done by the working substance during isothermal expansion (ii) the work done on the substance during isothermal compression (iii) the efficiency of the ideal engine.

Derive an expansions for the work done in one cycle during adiabatic expansion.