Heat is best defined as
a. friction.
b. temperature.
c. the flow of matter from one point to another.
d. energy in the motion or vibration of molecules in a substance.
There can be someone who think answer should be B but temperature isn' proportional with heat. The formula is Q=m.c.t , so it isn't definetly temperature. So answer should be D. Because A and C connect with force etc.
