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?

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)) .

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

An adiabatic vessel of total volume V is divided into two equal parts by a conducting separator. The separator is fixed in this position. The part on the left contains one mole of an ideal gas (U=1.5 nRT) and the part on the right contains two moles of the same gas. initially, the pressure on each side is p. the system is left for sufficient time so that a steady state is reached. find (a) the work done by the gas in the left part during the process, (b) the temperature on the two sides in the beginning, (c ) the final common temperature reached by the gases, (d) the heat given to the gas in the right part and (e) the increase in the internal energy of the gas in the left part.

A silver ball of radius 4.8 cm is suspended by a thread in a vacuum chamber, Ultraviolet light of wavelength 200nm is incident on the ball for some time during which a total light energy of 1.0 xx 10^-7 J falls on the surface. Assuming that on the average one photon out of every ten thousand is able to eject a photoelectron, find the electric potential at the surface of the ball assuming zero potential at infinity. What is the potential at the centre of the ball?

A ball of mass 0.5 kg thrown upwards reaches a maximum height of 5m.Calculate the work done by the force of gravity during this vertical displacement considering the value of g =10m//s^(2) .