How far apart should two protons be if the electrical force of repulsion on each one is equal to its weight on the earth? ( k = 1/4πε 0 = 9.0 × 10 9 N ∙ m 2/C 2, e = 1.6 × 10^ -19 C, m proton = 1.67 × 10^ -27 kg)

Iflow from a warmer object to a cooler object until both objects are the same temperature what am i?

An engineer designs a roller coaster so that a car travels horizontally for 152 ft, then climbs 137 ft at an angle of 34.0° above the horizontal. it then moves 137 ft at an angle of 48.0° below the horizontal. if we take the initial horizontal motion of the car to be along the +x-axis, what is the car's displacement? (give the magnitude of your answer, in ft, to at least four significant figures and give the direction of your answer in degrees counterclockwise from the +x-axis.)

Which of the following is the main energy source for the sun? a. fission of hydrogen b. fusion of hydrogen c. fusion of helium d. fission of iron