Power

Water falls down a $500.0 \mathrm{m}$ shaft to reach a turbine which generates electricity. How much water must fall per second in order to generate $1.00\times {10}^9$ watts of power ? (Assume $50\%$ efficiency of conversion and $g=10 \mathrm{m} {\mathrm{s}}^{-1}$)

A girl of mass $50 \mathrm{kg}$ swinging on a cradle. If she moves with a velocity of $2 \mathrm{m} {\mathrm{s}}^{-1}$ upwards in a direction making an angle $60°$ with the vertical, then the power generated is $\left(g=9.8 \mathrm{m} {\mathrm{s}}^{-2}\right)$

A body is initially at rest. It undergoes one-dimensional motion with constant acceleration. The power delivered to it at time $t$ is proportional to:

An engine develops $10 \mathrm{kW}$ of power. The time it will take in lifting a mass of  $200 \mathrm{kg}$ to a height of $40 \mathrm{m}. (\mathrm{g}=10 \mathrm{m}/{\mathrm{s}}^2)$ is:

Water falls from a height of  $60 \mathrm{m}$ at the rate of  $15 \mathrm{kg}/\mathrm{s}$ to operate a turbine. The losses due to frictional forces are $10\%$  of energy. How much power is generated by the turbine? $(\mathrm{g}=10 \mathrm{m}/{\mathrm{s}}^2)$.

A tube-well pumps out $2400 \mathrm{kg}$ of water per $\mathrm{minute}$. If the water is coming out with a velocity of $3 \mathrm{m} {\mathrm{s}}^{-1}$, then the power of the pump is

An engine pumps up $1000 \mathrm{kg}$ of coal from a mine $100 \mathrm{m}$ deep in $0.5 \sec$. The pump is running with diesel and efficiency of diesel engine is $25\%$. Then its power consumption will be $\left(g=10 \mathrm{m} {\sec }^{-2}\right)$

A block of mass $m$ slides along the horizontal track with kinetic friction $\mu .$ A man pulls the block through a light rope which makes an angle $\mathrm{\theta }$ with the horizontal as shown in the figure. The tension in the light rope is $T$ as shown. The block moves with constant speed $v$. Power delivered by the man to the block is 

An elevator can carry a maximum load of $1000 \mathrm{kg}$ is moving up with a constant speed of $2 \mathrm{m} {\mathrm{s}}^{-1}$. The frictional force opposing the motion is $2000 \mathrm{N}$. The minimum power delivered by the motor to the elevator is (Assuming $g=10 \mathrm{m} {\mathrm{s}}^{-2}$)

_____is the rate of doing work or the rate of transfer of energy.

Watt is the unit of _____.

Formula for power is _____.

_____is the amount of energy consumed when an electric appliance having a power rating of 1 Kilowatt is used for 1 hour. 

Which one of the following is not the unit of energy?

Which one of the following is not the unit of energy?

Horsepower is the unit of _____

what is the relation between horsepower and watt?

_____ is a scalar quantity as it has only magnitude and no direction.

Work done is _____when the applied force acts opposite to the direction of displacement.

_____ is the rate of doing work or work done per unit time.