Light passes from a material with index of refraction 1.25 to one with index of refraction 1.72. the angle of incidence is 34.3°. what is the angle of refraction?

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?

Which lists the amplitudes of sound waves from these sources in order from greatest to least? busy roadway, kids whispering, average home chainsaw, diesel truck, rustling leaves kids whispering, vacuum cleaner, jet airplane library, conversational speech, music from speaker

List and describe three ways that humans can change ecosystems and three ways that humans can protect ecosystems.