Work Energy And Power

An open knife edge of mass m is dropped from a height on a wooden floor. If the blade penetrates distance into the wood, the average resistance offered by the wood to the blade is

Two springs and are identical but is harder than . Let and represent the work done when the springs are stretched through the same distance and and are the work done when these are stretched by equal forces, then which of the following is true?

A particle of mass moving with speed towards east strikes another particle of same mass moving with same speed towards north. After striking, the two particles fuse together. With what speed this new particle of mass will move in north-east direction?

A particle in a certain conservative force field has a potential energy given by . The force exerted on it is

A sphere of mass m and velocity - undergoes an oblique and perfectly elastic collision with an identical sphere initially at rest. The angle between the velocities of the spheres after the collision shall be

Figure gives the acceleration of a body as it moves from rest along axis while a variable force acts on it from to . The work done by the force on the body when it reaches (i) and (ii) shall be as given below

The only force acting on a body that is moving in plane has a magnitude of . The body initially has a velocity of in the positive -direction. Some time later, the body has a velocity of in the positive direction. The work done on the body by the force during this time is

The graphs below show the magnitude of the force on a particle as it moves along the positive -axis from the origin to . The force is parallel to the -axis and conservative. The maximum magnitude has the same value for all graphs. Rank the situations according to the change in the potential energy associated with the force, least (or most negative) to greatest (or most positive).