How would you solve these?

What is the average speed of a car that travels 40 mph for 1 hour and 60 mph in another hour?

What is friction? how does it affect the motion of an object?

On your wedding day your lover gives you a gold ring of mass 3.67 g. 48 years later its mass is 3.44 g. on the average how many atoms were abrated from the ring during each second of your marriage? the atomic mass of gold is 197 u. don't enter units