Aforce of 20 newtons is required to push a 30 kg cart 40 meters across a room. from this effort, how many joules of work are performed?

800 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 with distance .  

Work 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 (as this case), the equation to calculate it is:  

Where:

Then:

answer would be letter choice (a),   a ball resting on a shelf. would be another example of potential energy   >   stored energy > not moving.

a ball spinning on a finger   >   kinetic energy > moving energy

a ball rolling on the ground   >   kinetic energy   > moving energy

a   ball flying through the air   > kinetic energy   >   moving energy

hope that                                         : )