A horizontal line means the object is moving at a constant speed. The gradient of the line = the rate of change of speed. The steeper the line, the greater the increase in speed. The area under the ...

When a relationship between two variables is defined by a curve it means that the gradient, or rate of change, is always varying. An average speed for a journey can be found from a distance-time graph ...

Whether you should focus on top speed or acceleration in a performance car is a subject that has been debated for nearly as ...

Time is not absolute, with gravity and velocity affecting how fast it passes, making clocks at different heights or near ...