A machine lifts up a load of $500 k g$ by a height of $2 m$ . Calculate the efficiency of the machine if the energy input to the machine is $25000 J$ . (Take $g = 10 m s^{- 2}$ ).
0.4

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Solution

The correct option is A 0.4
Mass, $m = 500 k g$
$g = 10 m s^{- 2}$
Height, $h = 2 m$

We know,
Efficiency, $η = \frac{W_{O u t p u t}}{W_{I n p u t}}$
Output work, $W_{O u t p u t} = m g h = 500 \times 10 \times 2$
$= 10000 J$
Input work,
$W_{I n p u t} = 25000 J$

$∴ E f f i c i e n y, η = \frac{10000}{25000}$
$= 0.4$

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A machine lifts up a load of 500 kg by a height of 2 m. Calculate the efficiency of the machine if the energy input to the machine is 25000 J. (Take g=10 ms−2).0.4

The correct option is A 0.4Mass, m=500 kg g=10 ms−2 Height, h=2 m We know, Efficiency, η=WOutputWInput Output work, WOutput=mgh=500×10×2 =10000 J Input work, WInput=25000 J ∴Efficieny,η=1000025000 =0.4

A machine lifts up a load of $500 k g$ by a height of $2 m$ . Calculate the efficiency of the machine if the energy input to the machine is $25000 J$ . (Take $g = 10 m s^{- 2}$ ).
0.4