Which best supports the idea that the surface of the moon has changed very little?

a) if photographs of the moon were taken millions of years ago, the surface would look the same.
b) because the moon does not have a large iron core, it is not possible for geologic events to occur on the moon.
c) because the moon has no atmosphere, it is not possible for geologic events to occur on the moon.
d) if one considers the history of the moon, there is only one distinct phase of its development.

Suppose that a mass of 2 kg is attached a spring whose spring constant is 50. the system is damped such that b = 12 . the mass is set in motion with an initial velocity of -8 m/s at a position 0 meters from equilibrium. set up and solve a differential equation that models this motion. write your solution in the form a cos ( ω t − α ) where α is a positive number. use your solution to fill in the information below: what is the amplitude of the motion? what is the value of ω ? what is the phase shift?