Which of the following is true for a system consisting of a mass oscillating on the end of an ideal spring?

a. the kinetic and potential energies are equal at all times.
b. the kinetic and potential energies are both constant.
c. the maximum potential energy is achieved when the mass passes through its equilibrium position.
d. the maximum kinetic energy and maximum potential energy are equal, but occur at different times.
e. the maximum kinetic energy occurs at maximum displacement of the mass from its equilibrium position.

Samir watches a 100-minute movie on his spaceship. maria's spaceshipe flies in the same direction as samir's spaceship but she observes his move to last 125 minutes and his spaceship to be 40 m long. how long does samir observe his own spaceship to be? according to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does marias voyage take according to samir?

How is zig zagging a form of acceleration?

Place me with this question is my last question