in the formula to calculate the change in thermal energy why is the triangle symbol used infron of the T but..

Question

not in front of the Q?

Answer 1

It technically should be in front of the Q as well since the upside down triangle, the Greek letter capital delta, is used as short hand for "the change in...". Thus, the equation you are looking at should read" The change in heat energy is equal to the mass time the specfic heat of a substance time the change in the substance's temperature".

It really is the change in energy that is measured - not the energy itself.

Answer 2

The "triangle" is the Greek capital letter delta. It symbolizes a change in whatever. For example deltaT = T1 - T0; where T1 and T0 are two different temperatures.

The change in thermal energy over time dQ/dt = kA deltaT/L, which simply shows that for a given cross sectional area A, thermal conductivity k, and thickness L between T1 and T0 the rate of change is proportional to delta T. What this tells us in practical terms is that as the two temperatures cool (T1) and heat up (T0), the rate of flow of heat will approach zero. And when T1 = T0, then dQ/dt = 0 and the system is in equilibrium.

Answer 3

What exactly is an "upside-down" triangle? Kind of like a "backwards square"?

The Greek delta is the symbol used to mean "change in" and if written wrong could be considered an upside-down letter but not triangle!