Tag: energy and its forms

A body of mass $10kg$ is moving along positive $x-$axis with $5\ m/s$ at $t=0$ and is moving along negative $x-$axis with same speed at $t=10\ s$. Average power of the force acting on the body is:

A light bulb has the rating 100 W, 220 V. If the supply voltage is 110 V, then power consumed by the bulb is

A force $\vec {F}=(3\hat {i}+4\hat {j})N$ acts on $2kg$ movable object that moves from an initial position $\vec {r} _{1}=(-3\hat {i}-2\hat {j})m$ to a final position $\vec {r} _{1}=(5\hat {i}+4\hat {j})m$ in $6s$. The average power delivered by the force during the interval of $6s$ is equal to :

A weight lifter lifts $300\ kg$ from the ground to a height of $2$ meter in $3$ seconds. The average power generated by him is:-

Human heart pumps $70\ cc$ of blood at each beat against a pressure of $125\ mm$ of $Hg$. If the pulse frequency is $72$ per minute, the power of the heat is nearly.

A force F acting on a body depends on its displacement $S$ as $F \propto S^{1/3}$. The power delivered by $F$ will depend on displacement as:

An engine of ine metric ton is going up an inclined plane, 1 in 2 at the rate of 36 kmph. If the coefficient of friction is $1/ \sqrt{3}$, the power of engine is 

A train of mass $6 \times 10^2$ metric tones is pulled by a locomotive. The speed of the train will be $36 \,kmhr^{}-1$. The locomotive pulls the train on the train on the level track, whose mass is $125$ metric tones. The force of friction acts on the locomotive and the train is $1 \times 10^1$ newton per metric tonne. Calculate the power of the locomotive.

The power of water pump is The power of water pump is  $4kW.$  If  $\left( g=10{ m }{ { s }^{ -2 } } \right) ,$  the amount of water it can raise in $1$ minute to a height of $20 m$  is then

An object of mass accelerates uniformly from rest to a speed $v _f$ in time $t _f$ Then the instantaneous power delivered to the object,as a function of time $t$ is -