# A total of 640 joules of work is done on a 50.-kilogram object as it is moved 8.0 meters across a level floor by the application of a horizontal force. What is the magnitude of the horizontal force applied to the object?

Sep 20, 2017

The force is 80 N.

#### Explanation:

Work is the product of force, displacement, and the cosine of the angle between them. In this case, it says that the work done is 640 J, displacement is 8.0 m. It also says that the force is horizontal, so the angle between force and displacement is zero.

Therefore,
$640 J = F \cdot 8.0 m \cdot \cos 0 = F \cdot 8.0 m$

Solving for F,
$F = \frac{640 J}{8.0 m} = 80 N$

I hope this helps,
Steve