A block-and-tackle system is used to lift a load of 20N through a vertical height of 10m. if the efficiency of the system is 40%, how much work is done agai...

Question 1 Report

A block-and-tackle system is used to lift a load of 20N through a vertical height of 10m. if the efficiency of the system is 40%, how much work is done against friction?

80J

120J

300J

500J

Answer Details

Efficiency = $\frac{o u t p u t}{i n p u t}$ x 100

40 = $\frac{20 \times 10}{i n p u t}$ x $\frac{100}{1}$

input = 500J

work against friction = input - output

= 500 - 200 = 300J

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Simple Machines

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