A 3.0 kg block starts at rest and slides a distance d down a frictionless 32.0° incline, where it runs into a spring. The block slides an additional 24.0 cm before it is brought to rest momentarily by compressing the spring, whose spring constant is 439 N/m. What is the value of d? img:http://i242.photobucket.com/albums/ff106/jtdla/prob01a.gif I'm not sure how to start this. I'm not sure how to calculate potential/kinetic energy (which was suppose to be the theme of the homework). I'm aware that this problem uses Hooke's law, but I'm not sure how to put it all together. A small block of mass m = 2.0 kg slides, without friction, along the loop-the-loop track shown. The block starts from the point P a distance h = 53.0 m above the bottom of the loop of radius R = 20.0 m. What is the kinetic energy of the mass at the point A on the loop? img:http://i242.photobucket.com/albums/ff106/jtdla/prob17a.gif Outside of the potential energy, I'm not sure how kinetic energy works in a circle. Or it its no different. I'm not sure if this assumption is correct, shouldn't the PE at the top of the track equal the KE at the bottom of the loop. Would that KE then equal the PE for the look itself. I'm not sure at all how to do these problems. This conservation of energy has been really tricky for me.