A person carrying 10 bricks each of mass 2.5 kg. on his head moves to a height 20 metres in 50 seconds. Calculate the power spent in carrying bricks of the person.

A man whose mass is 50 kg climbs up 30 steps of a stair in 30 s. If each step is 20 cm high, calculate the power used in climbing stairs.

A person trying to lose weight (dieter) lifts a 10 kg mass, one thousand times, to a height of 0.5 m each time. Assume that the potential energy lost each time she lowers the massis dissipated:- How much work does she do against thegravitational force ?

A person trying to lose weight (dieter) lifts a 10 kg mass, one thousand times, to a height of 0.5 m each time. Assume that the potential energy lost each time she lowers the massis dissipated:- Fat supplies 3.8 xx 10^7J of energy per kilogram which is converted to mechanical energy with a 20% efficiency rate. How much fat will the dieter use up?

An object of mass 1 kg travelling in straight line with a velocity of 10 ms^(-1) collides with it and sticks to a stationary wooden block of mass 5 kg. Then both move off together in the same straight line. Calculate the total momentum before the impact and just after the impact. Also calculate the velocity of combined object.

If a man lifts a load up with the help of rope such that it raises the load of mass 50 kg to a height of 20 m in 100 seconds. Find the power of man. (Take g = 10ms^-2 )

Four sphere each of mass 10 kg and of radius 20 cm are placed at the four cornes of a square of side 100 cm. Calculate the moment of inertia of the system about an axis coinciding with side of the square (given moment of inertia of sphere = 2/5 MR^2 )