Problem #29 on p.162
The only force acting on a 2.0 kg body as it moves along a positive x axis has an x component Fx = -6x N, with x in meters.
The velocity at x = 3.0 m is 8.0 m/s.
(a) What is the velocity of the body at x = 4.0 m?
(b) At what positive value of x will the body have a velocity of 5.0 m/s?
solution #1 - solves the problem using the work-kinetic energy theorem.
The net work done by the spring equals the change in kinetic energy of the object attached to the spring.
solution #2 - solves the problem using the equations that describe displacement and velocity in simple harmonic motion.
This solution also uses equation 15-12 that relates angular frequency to the mass of the object and the k constant of the spring.
solution #3 - solves the problem using the conservation of energy.
The total amount of energy is the sum of the potential (U) and the kinetic (K) energies and is a constant.