Answer:
Efficiency: 0.4 (40%)
Explanation:
The efficiency of a simple machine is given by the ratio
n = w¹/w²
where
w² is the input work of the machine
w¹ is the output work of the machine
For the machine in this problem, we have:
w¹ = 800j is the output work
w² = 2000j is the input work
Therefore, the efficiency of the machine is
n = 800/2000 = 0.4
Which can be also written as percentage:
n = 0.4 × 100 = 40%
hope it helps you
