In: Physics
Which requires more work, lifting a 25 -kg load a vertical distance of 8.5 meters or lifting a 15-kg load a vertical distance of 17 m?
solution
work required to lift a mass m through a height of h = force x distance
force = weight ( mg)
= (mg)
where g is acceleration due to gravity ,whose numerical value is 9.8 m/s2
work = mg x h
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Work required to lift a 25 -kg load a vertical distance of 8.5 meters = 25kg x 8.5m x 9.8 m/s2 = 2082.5 joules
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Work required to lift a 15 -kg load a vertical distance of 17 meters = 15kg x 17 m x 9.8 m/s2 = 2499 joules
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Therefore lifting a 15 -kg load a vertical distance of 17 meters requires more work than lifting a 25-kg load a vertical distance of 8.5 m .