Question

If the work put into a lever is 25.0 joules and the work done by the lever is 20.0 joules, what is the efficiency of the lever? 100% because energy must be conserved. 80.0% 45.0% 5.0%

Answer 1

80% , hope this helps 

Answer 2

Answer: The efficiency of the lever is 80%.

Step-by-step explanation:

An efficiency is the measure of how much wok or energy is conserved in a given process. It is defined as the ratio of output work and input work. If the energy is totally conserved in a process, the the percentage efficiency will be 100%.

Mathematically,

`\%\text{ efficiency}=(W_(out))/(W_(in))* 100`

Where,

`W_(out)` = Work done by the lever = 20 J

`W_(in)` = Work put in the lever = 25 J

Putting values in above equation, we get:

`\%\text{ efficiency}=(20)/(25)* 100\\\\\%\text{ efficiency}=80\%`

Hence, the efficiency of the lever is 80%.