Motion is the distance one object moves That seems easy enough, except for one fact. Everything is moving. You may seem to be sitting still in front of your computer, but both you and your computer is moving through space. So before you can measure how far something moves you have to establish a reference point. |
Are the stairs moving under the motorcycle, or is the motorcycle moving over the stairs? The answer depends upon your reference point. |
The reference point is the thing that you measure motion against. You may want to think of it as the thing that is standing still. |