The work W (in joules) done when lifting an object varies jointly with the mass m (in kilograms) of the object and the height h (in meters) that the object is lifted. The work done when a 120-kilogram object is lifted 1.8 meters is 2116.8 joules. How much work is done when lifting a 190-kilogram object 1.5 meters?
A) 2813 J
B) 2773 J
C) 2793 J
D) 2803 J
E) 2783 J

Question

Quizplus · Accepted Answer

We can set up a proportion using the given information:
Work/mass*height = k
where k is a constant. 
Plugging in the first set of values, we get:
2116.8/120*1.8 = k
Simplifying, we get k = 11.7. 
Now we can use this value of k to solve the second part of the problem:
Work/190*1.5 = 11.7
Solving for Work, we get Work = 2793 J. 
Therefore, the answer is choice C.

The Work W (In Joules) Done When Lifting an Object