Editor's Note: The Hyperloop is a totally imaginary transportation device that has captivated entrepreneur Elon Musk, who keeps talking about it. First imagined at least 100 years ago, it would ...

Determining acceleration If an object moves along a straight line, its motion can be represented by a velocity-time graph. The gradient of the line is equal to the acceleration of the object. The ...

A negative gradient shows the rate of “slowing down” or deceleration. Velocity-time graphs show velocity on the vertical axis. Acceleration is still represented by the gradient. Key fact The gradient ...