Asailor pulls a 2,000 kilogram boat 25 meters along the dock with a rope attached to the boat that makes a 45 degree angle with the dock. how much work is done by the sailor if he exerts a force of 400 newtons while pulling the boat?

7071.067 Joules

Explanation:

The Work done by a Force refers to the release of potential energy from a body that is moved by the application of that force to overcome a resistance along a path .  

It should be noted that it is a scalar, and its unit in the International System of Units is the Joule (like energy). Therefore, 1 Joule is the work done by a force of 1 Newton when moving an object, in the direction of the force, along 1 meter:  

Now, when the applied force is constant and the direction of the force and the direction of the movement are parallel, the equation to calculate it is:  

(1)

When they are not parallel, both directions form an angle, let's call it . In that case the expression to calculate the Work is:  

(2)

In this case the force and the distance in the path form an angle , so we will use the second equation, where and :

(3)

Then: