The cart then detects motion over these lines to give position-time data. Again using the quadratic fit I can find the acceleration. In this case it gives a value of 0.1092 m/s 2 .

Remember, acceleration is the same as gradient, and acceleration = velocity change ÷ time. Look at the graph. The acceleration of the vehicle in the first 10 seconds is: ...

If I know the mass of the cart (which I do—it's 0.566 kilograms), then the product of the mass and acceleration gives the force. That means in this case the impact force is 2.04 newtons.

Learn the uses of equations and graphs of motion and how to determine other aspects of the motion of objects. BBC Bitesize Scotland Higher Physics revision.