A machine rated as 150W, changes the velocity of a 10kg mass from 4m/s to 10m/s in 4s. The efficiency of the machine is nearly :

A force applied by an engine of a train of mass 2.05xx10^6 kg changes its velocity from 5 m/s to 25 m/s in 5 minutes. The power of the engine is

A missile is fired for maximum range with an initial velocity of 20m//s . If g=10m//s^(2) , the range of the missile is

In the figure shown the man of mass 60kg is lowering a block of mass 10kg with an acceleration of 2m//s^2 . Find the reading of the machine.

In the figure shown the man of mass 60kg is lowering a block of mass 10kg with an acceleration of 2m//s^2 . Find the reading of the machine.

A rocket of total mass 1000kg initially is launched from ground. The gases are ejected at the rate 20kg/s with velocity 1000 m/s relative to rocket vertically downwards. The initial acceleration of the rocket is a (in m//s^(2) ). Find a/g . (Take g=10 m//s^(2) )

Certain force acting on a 20 kg mass changes its velocity from 5m//s to 2m//s . calculate the work done by the force.

A machine raises a laod a 750 N through a height of 16 m in 5 s.Calculate: (i)the energy spent by the machine , (ii)the power of the machine if it is 100 % efficient.

A cylinder of 10 kg is sliding in a plane with an initial velocity of 10 m / s . If the coefficient of friction between the surface and cylinder is 0.5 then before stopping, it will cover. (g=10m//s^(2))

An object of mass 5 kg falls from rest through a vertical distance of 20 m and attains a velocity of 10 m/s. How much work is done by the resistance of the air on the object? (g=10m//s^(2)) .

An object of mass 5 kg falls from rest through a vertical distance of 20 m and attains a velocity of 10 m/s. How much work is done by the resistance of the air on the object? (g=10m//s^(2)) .