- Relate (without calculation) work done to the magnitude of a force and the distance moved.
Work done is the product of the force applied on the object and the straight-line distance it moves, provided that the force is in the same direction as the motion of the object.
- Describe energy changes in terms of work done.
When a ball free falls, gravity is doing work on the object. This work causes the conversion of potential energy to kinetic energy.
If you push a box across a smooth surface, pretend that you use 500J of energy. Some of that energy is lost as sound and heat, but the rest is used to do work on the box. So, if 1J is lost as heat energy and sound energy, you are doing 499J of work on the box, so the box gains a KE of 499J.
Remember, work done = energy transferred
Doing work simply means that the energy may be transferred to another object, or converted to another form.
- Recall and use W = F x d
W = Fd
Where W is work done, measured in J,
F is the force applied on the object, provided the force is in the same direction that the object moves, measured in N,
And d is the displacement (which is the straight-line distance) moved by the object, measured in m.
Notes submitted by Sarah.
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