I know that the net work = the change in kinetic energy, delta KE. But what if the object has both the potential energy and kinetic energy, for example, a falling object, then how can I find out the work done on the object at a particular point? Still the change in KE ignore PE?(adsbygoogle = window.adsbygoogle || []).push({});

Also, I know the external work = the change in potential enery, delta PE. It happens in a lifting a brick, but Is that the net work? What's the difference? In addition, work done by gravity=-delta PE. If I am asked to find out the net work, should I plus together the external work and work done by gravity? In this lifting case, is there a kinetic energy? Can I find out the net work by using change in KE? I am confused with some concepts, hope you can help. thanks.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Work and change in kinetic energy

**Physics Forums | Science Articles, Homework Help, Discussion**