The average power required to lift a 100 kg mass through a height of 50 metres in approximately 50 seconds would be 

(1) 50 J/s

(2) 5000 J/s

(3) 100 J/s

(4) 980 J/s

The power of a pump, which can pump 200kg of water to a height of 200m in 10sec is (g = 10 m/s²) 

(1) 40 kW

(2) 80 kW

(3) 400 kW

(4) 960 kW

A 60 kg man runs up a staircase in 12 seconds while a 50 kg man runs up the same staircase in 11, seconds, the ratio of the rate of doing their work is 

(1) 6 : 5

(2) 12 : 11

(3) 11 : 10

(4) 10 : 11

What average horsepower is developed by an 80 kg man while climbing in 10 s a flight of stairs that rises 6 m vertically 

(1) 0.63 HP

(2) 1.26 HP

(3) 1.8 HP

(4) 2.1 HP

An engine pumps up 100 kg of water through a height of 10 m in 5 s. Given that the efficiency of the engine is 60% . If g = 10 ms^–2, the power of the engine is

(1) 3.3 kW

(2) 0.33 kW

(3) 0.033 kW

(4) 33 kW

An engine pump is used to pump a liquid of density ρ continuously through a pipe of cross-sectional area A. If the speed of flow of the liquid in the pipe is v, then the rate at which kinetic energy is being imparted to the liquid is

(1) $\frac{1}{2}A\rho v^3$

(2) $\frac{1}{2}A\rho v^2$

(3) $\frac{1}{2}A\rho v$

(4) $A\rho v$

A uniform chain of length \(L\) and mass \(M\) is lying on a smooth table and one-third of its length is hanging vertically down over the edge of the table. If \(g\) is the acceleration due to gravity, the work required to pull the hanging part on the table is:
1. \(MgL\)

2. \(\dfrac{MgL}{3}\)

3. \(\dfrac{MgL}{9}\)

4. \(\dfrac{MgL}{18}\)

If W₁, W₂ and W₃ represent the work done in moving a particle from A to B along three different paths 1, 2 and 3 respectively (as shown) in the gravitational field of a point mass m, find the correct relation between W₁, W₂ and W₃ 

(1) W₁ > W₂ > W₃

(2) W₁ = W₂ = W₃

(3) W₁ < W₂ < W₃

(4) W₂ > W₁ > W₃