Untitled

A ball is projected vertically down with an initial velocity from a height of 20 m on to a horizontal floor. During the impact it loses 50% of its energy and rebounds to the same height, the initial velocity of its projection is-

A 1.0 HP motor pump out water from a well of depth 20 m and fills a water tank of volume 2238 litres at a height of 10 m from the ground. The running time of the motor to fill the empty water tank is ( \( \mathrm{g}=10 \mathrm{~ms}^{-2} \) )

A suspended simple pendulum of length \( l \) is making an angle \( \theta \) with the vertical. On releasing, its velocity at lowest point will be-

A uniform chain of length \( L \) and mass \( M \) is lying on a smooth table and \( 1/3 \) of its length is hanging down over the edge of the table. If \( g \) is the acceleration due to gravity, the work done to pull the hanging part on the table is

A ball released from a certain height which loses \(50\%\) of its K.E. on striking the ground. It will attain a height again -

The work done against gravity in taking 10 kg mass at 1 m height in 1 sec will be -

A swing is at 1 m height above ground level in its lowermost position and 3 m in middle position. Its speed at lowest position of vertical circle is -

A force of 10 N displaces an object by 10 m. If work done is 50 J then direction of force make an angle with direction of displacement –

A body moves along the straight line by a machine delivering constant power. The distance moved by the body in time \( t \) is proportional to

The kinetic energy of a body becomes four times its initial value. The new linear momentum will be

A body of mass 10 kg is falling from a height of 1 m then at bottom gain in kinetic energy is

If a spring extends by x on loading then energy stored by the spring is

Water is falling on the blades of a turbine at a rate of \( 100 \mathrm{~kg} / \mathrm{sec} \) from a certain spring. If the height of the spring be 100 meters, the power transferred to the turbine will be

Two springs A and B having spring constants \(K_{A}\) and \(K_{B}\) (\(K_{A}=2K_{B}\)) are stretched by applying force of equal magnitude. If energy stored in spring A is E then energy stored in B will be

A wind-powered generator converts wind energy into electrical energy. Assume that the generator converts a fixed fraction of the wind energy intercepted by its blades into electrical energy. For wind speed \(v\), the electrical power output will be proportional to–

In the figure to complete the circular loop what should be the radius if initial height is 5 m