A spring with a spring constant k = 30 N/m is on a frictionless incline with an angle of 40º.  A 4.0 kg object is hung on the spring and allowed to slide down the incline.  What is the speed of the object after it has slid a distance D = 0.7 m?  Hint:  Make potential energy zero at the stretch of D

A box is pressed against a horizontal spring, compressing the spring from its relaxed length. The box is then released and the spring launches the box horizontally along a track that ends in a ramp, as shown above. The box has enough speed to leave the ramp, and the box reaches a maximum vertical height above the floor. Assume there is negligible friction between the box and the track and air resistance is negligible.   K = spring constant of spring X = distance the spring is compressed M = mass box Theta = angle of ramp from horizontal H = maximum height reached by box   Does the mechanical energy of the box-spring-earth system increase, decrease, or remain the same from the moment the spring is released until just before the box hits the ground? Justify your answer. If air resistance were not negligible, how would that affect your answer, if at all? Justify your answer.

A bungee cord exerts a nonlinear elastic force of magnitude F(x) = k1x + k2x°, where x is the distance the cord is stretched, k1 = 205 N/m and k2 = -0.223 N/m³. How much work must be done on the cord to stretch it 16.7 m? W = kJ Submit Question

As shown in the figure, a 0.490kg object is pushed against a horizontal spring of negligible mass until the spring is compressed a distance x. The force constant of the spring is 450 N/m. When it is released, the object travels along a frictionless, horizontal surface to point A, the bottom of a vertical circular track of radius R = 1.00 m, and continues to move up the track. The speed of the object at the bottom of the track is va = 12.8 m/s and the object experiences an average frictional force of 7.00 N while sliding up the track. (a) What is x? (b)  If the object were to reach the top of the track, what would be it’s speed at that point? (c) Does the object actually reach the top of the track, or does it fall off before reaching the top?