Pls help

What distance with a 6 N weight expand a spring with a spring constant of 15 N/m?

What tightening torque should be used for a hexagonal head screw (not split-bolt) on a 250 kcmil conductor?

Which of the following correctly describes what happens when an atomic bomb explodes? small pieces of fissionable material are joined and form a body with a mass greater than the critical mass, the relative number of neutrons escaping decreases, and a chain reaction and explosion result. large pieces of fissionable matter are brought together quickly and form a body with a mass smaller than the critical mass, the relative number of escaping neutrons increases, and a chain reaction and explosion result.

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration