An engineer is designing a spring to be placed at the bottom of an elevator shaft. if the elevator cable should happen to break when the elevator is at a height h = 12.5 m above the top of the spring, calculate the value the spring constant k should have so that passengers undergo a maximum acceleration of 5.3g. take the mass of the elevators plus passengers to be m = 1439 kg.

The great sandini is a 60.0-kg circus performer who is shot from a cannon (actually a spring gun). you don’t find many men of his caliber, so you him design a new gun. this new gun has a very large spring with a very small mass and a force constant of 1100 n/m that he will compress with a force of 4400 n. the inside of the gun barrel is coated with teflon, so the average friction force will be only 40.0 n during the 4.00 m he moves in the barrel. at what speed will he emerge from the end of the barrel, 2.50 m above his initial rest position?