Select the correct answer. Which of these statements is true about heat?

A. heat always flows from cooler to warmer substances

B. heat doesn’t flow between substances

C. heat always flows from warmer so cooler substances

D. heat flows when both substances have the same temperature

Estimate the kinetic energy of the neptune with respect to the sun as the sum of the terms, that due to its daily rotation about its axis, and that due to its yearly revolution about the sun. [assume the neptune is a uniform sphere with mass = 1.0×1026 kg , radius = 2.5×1010 m , rotation period 16.1 h , orbital period 6.01×104 d and is 4.6×109 km from the sun.]