Q = hA(T∞ - Tw) is named after which scientist?

Q = hA(T∞ - Tw) is named after which scientist?

• A. Isaac Newton
• B. James Watt
• C. Daniel Bernoulli
• D. Albert Einstein

Answer: (A)

This is Newton's law of cooling: the rate of heat transfer by convection is proportional to the temperature difference between the object's surface and the surrounding fluid. In the given form, Q = hA(T∞ − Tw), h is the convective heat transfer coefficient and A is the surface area. The sign convention here makes Q positive when heat flows into the fluid; if Tw is higher than T∞, heat leaves the surface and Q becomes negative, while the magnitude is still governed by hA|T∞ − Tw|. This linear relationship between cooling rate and temperature difference is precisely what Isaac Newton described, so the equation bears his name. The other scientists—Watt for steam engine improvements, Bernoulli for fluid dynamics and pressure-energy concepts, Einstein for relativity and quantum effects—are associated with different foundational ideas, not this convection cooling law.

This is Newton's law of cooling: the rate of heat transfer by convection is proportional to the temperature difference between the object's surface and the surrounding fluid. In the given form, Q = hA(T∞ − Tw), h is the convective heat transfer coefficient and A is the surface area. The sign convention here makes Q positive when heat flows into the fluid; if Tw is higher than T∞, heat leaves the surface and Q becomes negative, while the magnitude is still governed by hA|T∞ − Tw|. This linear relationship between cooling rate and temperature difference is precisely what Isaac Newton described, so the equation bears his name. The other scientists—Watt for steam engine improvements, Bernoulli for fluid dynamics and pressure-energy concepts, Einstein for relativity and quantum effects—are associated with different foundational ideas, not this convection cooling law.