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 ...

Save guides, add subjects and pick up where you left off with your BBC account. The gradient of a velocity-time graph at a particular time gives the acceleration of the object at that time.

Velocity-time graphs show how the velocity (or speed) of a moving object changes with time. These graphs also show if the object is moving at a constant speed or accelerating, decelerating ...