Question

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A lawn mower is pushed with a force of 80 N. If 12,000 J of work are done in mowing a lawn, what is the total distance the lawn mower was pushed?

Answer 1

Given:

A lawn mower is pushed with a force of 80 N. 12,000 J of work are done in mowing a lawn.

To find:

Total distance pushed by lawn-mower ?

Calculation:

Work done by the lawn-mower can be expressed as :

$\sf \therefore \: W = F \times d \times \cos( \theta)$

• Here , "F" is force , "d" is displacement , $\theta$ is the angle between force vector and displacement vector.

• While pushing the lawn-mower, the angle will be 0°.

$\sf \implies\: W = F \times d \times \cos( {0}^{ \circ} )$

$\sf \implies\: W = F \times d$

$\sf \implies\: 12000 = 80 \times d$

$\sf \implies\: d = \dfrac{12000}{80}$

$\sf \implies\: d = 150 \: metres$

So, displacement (synonymous to distance in our case) is 150 metres.