
A ring of mass can slide over a smooth vertical rod. A light string attached to the ring passing over a smooth fixed pulley at a distance of from the rod as shown in the figure. At the other end of the string mass is attached, lying over a smooth fixed inclined plane of inclination angle The ring is held in level with the pulley and released. Determine the instantaneous power of the gravitational force acting on the ring (in watts) when the string makes an angle with the horizontal.



Important Questions on Work, Energy and Power
A mass of moving with a speed of on a horizontal smooth surface, collides with a nearly weightless spring of force constant . The maximum compression of the spring would be










(Take the radius of the drum to be 1.25 m and its axle to be horizontal) :







A large block of wood of mass is hanging from two long massless cords. A bullet of mass is fired into the block and gets embedded in it. The (block bullet) then swing upwards, their center of mass rising a vertical distance before the (block bullet) pendulum comes momentarily to rest at the end of its arc. The speed of the bullet just before the collision is: (Take )




A particle is released on a vertical smooth semicircular track from point so that, makes angle from the vertical (see figure). The normal reaction of the track on the particle vanishes at the point where makes an angle with the horizontal. Then


