The driver of a 1000 kg car is speeding. He loses control and collides with a wall, coming to a stop. The crumple zone of the car absorbed 90 kN of force in 0.5 seconds. What was the car's speed at the time of impact?

The nuclear potential that binds protons and neutrons in the nucleus of an atom is often approximated by a square well. imagine a proton conned in an innite square well of length 105 nm, a typical nuclear diameter. calculate the wavelength and energy associated with the photon that is emitted when the proton undergoes a transition from the rst excited state (n 2) to the ground state (n 1). in what region of the electromagnetic spectrum does this wavelength belong?