A spaceship moving with a velocity of 90m/s come to a complete stop in 18sec. And remains at rest for 12sec. Then it has traveled with a constant of 40m/s for 20sec A) velocity Vs time graph
B) displacement Vs time
C) calculate the total displacement for velocity- time graph

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?