Newton's Second Law states that force equals mass times acceleration. This can be investigated using a set-up like this one. You can use this set-up to investigate how changing two separate factors, ...

This is a classic introductory physics problem. Basically, you have a cart on a frictionless track (call this m 1) with a string that runs over a pulley to another mass hanging below (call this m 2).

This is what a velocity-time graph represents. It helps you calculate reaction time and the time it takes for a vehicle to stop. Look at the graph and answer the questions.