Question

If it takes 10 J of work to move a rock 15 meters in 5 seconds, what is the power?

Answer 1

Given:

Work done = 10 J

Distance travelled = 15 m

Time taken = 5 sec

To find:

Power exerted by the force

Concept:

Power is defined as the rate of doing work. In other words , we can say that power is the ratio of the work done to the time taken.

It is a scalar quantity having only magnitude and no direction. Power can also be calculated by the product of force and velocity of any object.

Calculation:

$power = \dfrac{work}{time}$

$= > power = \dfrac{10}{5}$

$= > power = 2 \: watt$

So the power exerted by the force is 2 W

Answer 2

The above Question states the following information -

If it takes 10 J of work to move a rock 15 meters in 5 seconds.

To Find - Power

We know that power is a ratio of work per unit time .

Here,

Work Done = 10 Joules as already provided in the question .

Time Taken to do the work = 5 Seconds

Hence, Power = { 10 / 5 } Watts = 2 Watts .

So, the final answer becomes -

The power required to move the rock by a displacement of 15 metres in 5 Seconds is 2 Watts .

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Additional Information -

The unit of power is Watt .

The unit of work is Joules.

Dimension Of Power - [ M . L ^ 2 . T ^ { -3 } ]

Dimension Of Work = [ M . L ^ 2 . T ^ {-2 } ]

Energy , Work and Quantity Of Heat have the same dimensions i.e, [ M . L ^ 2 . T ^ {-2 } ] .

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