Power, Force and Velocity

Q. A man is riding on a cycle with velocity 7.2 km/hr up a hill having a slope 1 in 20. The total mass of the man and cycle is 100 kg. The power of the man is

1. 125 W
2. 200 W
3. 175 W
4. 98 W

Q. 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. 
2. 
3. 
4. 

Q. A hoist operated by an electric motor has a mass of 500 kg. It raises a load of 300 kg vertically at a steady speed of 0.2 m/s. Frictional resistance can be taken to be constant at 1200 N. What is the power required?

1. 1.61 kW
2. 1.51 kW
3. 1.81 kW
4. 2.01 kW

Q. A car of 100 HP is moving with a constant velocity of 72 km/hour. The forward force exerted by the engine of the car is

1. 
2. 
3. 
4. 

Q.

A body is moved along a straight line by a machine delivering constant power.

The distance moved by the body in time t is proportional to

1. 

2. 

3. 

4. 

Q. A body is being moved along a straight line by a machine delivering a constant power. The distance covered by the body in time t is proportional to

1. 
2. 
3. 
4. 

Q. Water from a stream is falling on the blades of a turbine at the rate of 100kg/sec. If the height of the stream is 100m then the power delivered to the turbine is

1. 100 kw
2. 10 kw
3. 1 kw
4. 100 w

Q. An electric motor produces a tension of 4500N in a load lifting cable and rolls it at the rate of 2m/s. The power of the motor is

1. 9 kw
2. 15 kw
3. 225 kw
4. 

Q.

An ice cream has a marked value of 700 kcal. How many kilowatt hour of energy will it deliver to the body as it is digested

1. 0.81 kWh

2. 0.90 kWh

3. 1.11 kWh

4. 0.71 kWh

Q. A mass m falls from rest under the influence of gravity. Then the average power supplied to the mass by the force of gravity is

1. 
2. 
3. 
4. 
   where h is the distance the mass falls.