A 0.45 kg mass sliding on a horizontal frictionless surface is attached to one end of a horizontal spring (with k = 650 N/m) whose other end is fixed. The mass has a kinetic energy of 9.0 J as it passes through its equilibrium position (the point at which the spring force is zero). At what rate is the spring doing work on the mass when the spring is compressed 0.083 m and the mass is moving away from the equilibrium position?

A mass of 0.25 kg is attached to a spring whose spring constant is k = 25 N/m. The spring is compressed 0.35 m on a frictionless surface and released from rest. At what location is the kinetic energy at a maximum, what is the amount of kinetic energy, and what is the velocity of the mass at that point?

A spring that obeys Hooke's law is hung in a vertical orientation. The spring is stretched a total of 6.0 cm from its equilibrium length when a 2.0 kg mass hangs from it. The spring, mass system is then pulled downward by an external force which lengthens the spring an additional 10cm. While the spring is being extended what is the work done by the spring?

An object with a 2.00 kg mass moving along the positive x axis in the +x direction has a speed of v = 2.50 m/s at the position x = 0.500 m and a potential energy of U(x) = (−4.00 J · m)/x. Determine the following. (a) an expression for the x component of the force acting on the object at any position along the x axis (Use the following as necessary: x. Do not enter units in your expression.) Fx =    (b) work done on the object by this force acting on the object from x = 1.00 m to x = 1.94 m J(c) change in potential energy of the object as it travels from  x = 1.00 m to x = 1.94 m  J(d) total energy of the object at any point along the x axis J(e) maximum distance the object can travel from the origin in the +x direction m