A spring-powered mortar is used to launch 10-lb packages of fireworks into the air. The pa...

A spring-powered mortar is used to launch 10-lb packages of fireworks into the air. The package starts from rest with the spring compressed to a length of 6 in. The unstretched length of the spring is 30 in. If the spring constant is k = 1300 lb/ft, what is the magnitude of the velocity of the package as it leaves the mortal?