Work, Power and Energy Questions

Three blocks with masses m, 2m and 3m are connected by strings,as shown in the figure. After an upward force F is applied on block m, the masses move upward at constant speed v. What is the net force ...

A force , (where k is a positve constant) acts on a particle moving in the x-y plane. String from the origin, the particle is taking along the positve x-axis to the point (a, o) and parallel to the y-...

Under the action of a force, a 2 kg body moves such that its position x as a function of time is given by x = , where x is in meters and t is in sec. The work done by the force in the first two second...

A Carnot engine, having an efficiency of as heat engine, is used as a refrigerator. If the work done on the system is 10 J, the amount of energy absorbed from the reservoir at lower temperature is :-...

A mass m moves in a circle on a smooth horizontal plane with velocity v0 at a radius R0. The mass is attached to a string which passes through a smooth hole in the plane as shown. The tension in the s...

A block of mass 10 kg, moving in x direction with a constant speed of 10 m-1, is subjected to a retarding force F = 0.1 x J/m during its travel from x = 20 m to 30 m. Its final KE will be :...

Two similar springs P and Q have spring constants KP and KQ, such that KP > KQ. The are stretched, first by the same amount (case a,) then by the same force (case b). The work done by the springs W...

A particle of mass m is driven by a machine that delivers a constant power k watts. If the particle starts from rest the force on the particle at time t is :

A person trying to lose weight by burning fat lifts a mass of 10 kg upto a height of 1 m 1000 times. Assume that the potential energy lost each time he lowers the mass is dissipated. How much fat will...

Consider a drop of rain water having mass 1 g falling from a height of 1 km. It hits the ground with a speed of 50 m/s. Take 'g' constant with a value 10 m/s2. The work done by the (i) gravita...

The diagrams below show regions of equipotentials:- A positive charge is moved from A to B in each diagram....

A capacitor of 2μF is charged as shown in the diagram. When the switch S is turned to position 2, the percentage of its stored energy dissipated is:...

A body of mass 1 kg begins to move under the action of a time dependent force F→=(2t i^ + 3t2 j^), where i^ and j^ are unit vectors along x and y axis. What power w...

A particle is moving in a circular path of radius a under the action of an attractive potential U = - k2r2. Its total energy is :-...

Two pith balls carrying equal charges are suspended from a common point by strings of equal length, the equilibrium separation between them is r. Now the strings are rigidly clamped at half the height...

A uniform force of newton acts on a particle of mass 2 kg. Hence the particle is displaced from position meter to position meter. The work done by the force on the particle is :-...

A tennis ball is dropped on a horizontal smooth surface. It bounces back to its original position after hitting the surface. The force on the ball during the collision is proportional to the length of...

A particle of mass m is initially at rest at the origin. It is subjected to a force and starts moving along the x-axis. Its kinetic energy K changes with time as dK/dt = γt, where γ is a pos...

The work done on a particle of mass m by a force, (K being a constant of appropriate dimensions), when the particle is taken from the point (a, 0) to the point (0, a) along a circular path of radius a...

When a rubber-band is stretched by a distance x, it exerts a restoring force of magnitude F = ax + bx2 where a and b are constants. The work done in stretching the unstretched rubber-band by L is :...