4. Bill travels 400 m east in 20 seconds and then travels 300 m north in 20 seconds. a) What is the total distance traveled?
b) What is the total displacement?
c) What was his average speed?
d) What was his average velocity?
What is the answer

Which of the following list the divisions of the geologic time scale in order from longest to shortest

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?

Contrast the force of gravity between these pairs of objects: 1-kg mass and a 2-kg mass that are 1 m apart; a 1-kg mass and a 2-kg mass that are 2 m apart; and two 2=kg masses that are 1 m apart. i dont understand.