Most sodium atoms have an atomic mass of 23, but a few have atomic masses of 22 or 24. How do these isotopes differ from one another?
A. In the number of ions
B. In the number of neutrons
C. In the number of protons
D. In the number of electrons

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?