PLEASE HELP Captain Jack Sparrow hangs from the rigging of the Black Pearl. If Captain Jack Sparrow has a mass of 78 kg and is currently 8.7 m above the deck of the Black Pearl, what is his potential energy?

Equation for PE is mxgxh

If steel is more dense that lake water, why can a boat float

How does the kinetic energy of a charge change as the charge moves under the effect of an electric field from higher potential to lower potential? a.the kinetic energy increases.b.the kinetic energy decreases.c.the kinetic energy remains the same.d.the kinetic energy is always zero.

Carbon is allowed to diffuse through a steel plate 15 mm thick. the concentrations of carbon at the two faces are 0.65 and 0.30 kg c/m^3 fe, which are maintained constant. if the preexponential and activation energy are 6.2 x 10-7 m2 /s and 80,000 j/mol, respectively, compute the temperature at which the diffusion flux is 1.43 x 10^-9 kg/m^2 -s.