Physics Test - ...

A spring obeying the linear law F=−Kx is first compressed by 10cm and the work done is W₁. Next, it is compressed by another 10cm10cm, the work done now is W₂, then W₁:W₂ is:

A chain of mass m and length L is overhanging from the edge of a smooth horizontal table such that 3/4th of its length is lying on the table. The work done in pulling the chain completely on to the table is:

A uniform chain of length L hangs partly from a table which is kept in equilibrium by friction. The maximum length that can stand without slipping is l, then the coefficient of friction between the table and the chain is:

A body of mass m starting from rest is acted on by a force producing a velocity v=√(k×s) where k is a constant and s is displacement. The work done by the force in the first tt seconds is:

A ball of mass 0.2kg strikes an obstacle and moves at 60⁰ to its original direction. If its speed also changes from 20m/s to 10m/s, the magnitude of the impulse received by the ball is

A ball reaches a wall at 60 m/s along +ve X direction, and leaves the wall in the opposite direction with the same speed. Assuming that the mass of the ball as 50gm and the contact time is 0.02 second, the force exerted by the wall on the ball is

A 5000 kg rocket is set for vertical firing. The exhaust speed is 800ms⁻¹. To give an upward acceleration of 20ms⁻², the amount of gas ejected per second to supply the needed thrust is (g=10ms⁻²):

A body is acted on by a force given by F=(10+2t) N . The impulse received by the body during the first four seconds is

An impulse I given to a body changes its velocity from v₁ to v₂. The increase in the kinetic energy of the body is given by:

A hammer of mass M strikes a nail of mass mm with velocity of u ms⁻¹ and drives it a meters into a fixed block of wood. The average resistance of the wood to the penetration of the nail is: