What is the percent error equation and do you know how to use it?

Atomic nuclei of almost all elements consist of

Rank the automobiles based on the magnitude of the force needed to stop them, from largest to smallest.2000 kg car going 5m/s500 kg car going 20 m/s1000 kg car going20m/s500 kg car going10m/s1000 kg car going10/s4000 kg car going 5m/s 0 0 603

The law of reflection states that the angle of reflection is equal to the angle of