Melissa's favorite exercise equipment at the gym consists of various springs. in one exercise, she pulls a handle grip attached to the free end of a spring to 0.80 m from its unstrained position. the other end of the spring (spring constant = 45 n/m) is held in place by the equipment frame. what is the magnitude of the force that melissa is applying to the handle grip?

The formula for force exerted on/by a spring is 

F = k*e where k is the spring constant and x is the distance stretched from unstrained position. This should allow you to find what you need.

Using F = k x e, 

where k is the spring constant, 

and e is the extension, 

The F is her weight = 45 X 0.80 

= 36 N

kepler used the data from tycho blahe (his mentor) to construct the laws of planetary motion.

measure their densities same density, same sub