Question 121: Work, Energy and Power & Circular Motion

Question

A porter lifts a heavy suitcase of mass 80 kg and at the destination lowers it down by a distance of 80 cm with a constant velocity. Calculate the work done by the porter in lowering the suitcase.
(take g = 9.8 ms
$$-$$2
)

Accepted Answer

$$W =  - N 	imes \Delta x$$
$$ =  - 80 	imes 9.8 	imes {{80} \over {100}}$$
$$ =  - 627.2$$ J

Answer

+627.2 J

Answer

$$-$$62720.0 J

Answer

$$-$$627.2 J

Answer

784.0 J

Work, Energy and Power & Circular Motion

A porter lifts a heavy suitcase of mass 80 kg and at the destination lowers it down by a distance of 80 cm with a constant velocity. Calculate the work done by the porter in lowering the suitcase. (take g = 9.8 ms $-$2 )

Choose the correct answer: