An ideal horizontal spring-mass system is set into motion. At an instant when the mass passes through its equilibrium position: The potential energy in the spring is at its . The kinetic energy of the mass is at its . The magnitude of net force acting on the mass is at its .

the potential energy is zero, and the kinetic energy must be maximum

    F = 0

Explanation:

In this exercise you are asked to complete the sentences of a simple harmonic movement of a mass-spring system.

In this system mechanical energy is conserved

at the most extreme point the carousel potential energy is

          K_e = ½ k x²

the kinetic energy is zero for that stopped.

At the equilibrium point

the spring elongation is x = 0 so the potential energy is zero

and the kinetic energy must be maximum since total energy of the system is conserved

the spring force is

             F =- k x

as in the equilibrium position x = 0 this implies that the force is also zero

             F = 0

note: the given question is incomplete.

complete question is given below.

which is an example of kinetic energy?

a. the energy stored in ethanol  

b. a hockey puck sliding across the ice  

c. a compressed spring  

d. a ball sitting at the top of a ramp

solution: the kinetic energy is the energy posses by the virtue of the motion of the object.

in the given options, a, c and d are the example of potential energy because it is the energy posses by the virtue of the rest of the object. but option b has the kinetic energy as the object is in motion.

hence, a hockey puck sliding across the ice   is the apex example of kinetic energy.

so, the option (b) a hockey puck sliding across the ice   is the correct option.