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?

Efficiency of the lever is 80 %.

Explanation:

Given that, if the work put into a lever is 25.0 joules and the work done by the lever is 20.0 joules. We need to find the efficiency of the lever. The mathematical expression for the efficiency is given by :

Where

are output and input work respectively.

So, the efficiency of the lever is 80 %. Hence, this is the required solution.    

answer: question1

1,000 tons

question2

3: 8

question 3

store d

step-by-step explanation:

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards