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%

The efficiency of the lever is 80%.

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,

Where,

= Work done by the lever = 20 J

= Work put in the lever = 25 J

Putting values in above equation, we get:

Hence, the efficiency of the lever is 80%.

a displacement distance is size of displ

i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.