The force of gravity down on the boy= 300n
the boy's weight down on the floor= 300n
the floor's reaction force back up on the boy= 300n
his weight is evenly distributed over each foot
what is the net force on the boy?

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.

Distinguish between linear momentum and angular momentum

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?