Remember velocity = distance/time so that mean you would do 60/3 which equals 20 so the speed(velocity) equals 20
I've actually used the magnet test to determine if a gold necklace of mine was real or not. If the gold item aka the crown is attracted to a magnet, it is definitely not real gold.if it isn't then its real gold.
A computer screen is energy transfer
Protons: charge +1, have a mass of 1 and are found in the nucleus
Neutrons: charge 0, have a mass of 1 and are found in the nucleus
Electrons: charge -1, have a mass of 1/840 and are found on the outside of the nucleus
hope that helps