If the average amount of earthquakes with a magnitude of 4 or higher was 10,000 per year, approximately how many would have registered as 6 or higher

Suppose that 27 j of work is needed to stretch a spring from its natural length of 6 m to a length of 9 m. (a) how much work is needed to stretch the spring from 12 m to 14 m? j (b) how far beyond its natural length will a force of 78 n keep the spring stretched?

In which of the following is positive work done by a person on a suitcase

The force needed to overcome static friction is usually less than that needed to overcome kinetic friction.true or false?