Write vector expressions for the position vector in unit-vector form for these two points. (b) what is the displacement vector?

Due in 40 explain in terms of frame of reference if you’re inside a moving train everything on the outside can seem to be moving

First answer marked as brainiest which is the correct equation describing the first law of thermodynamics? a) when the internal energy of a system changes, it equals the amount of heat added plus the work done. b) when work is done by the piston, it is equal to the heat added plus the change in internal energy of the system. c) when heat is added to the system, it is equal to the amount of work done by the piston plus the change in internal energy of the system.

Thermal radiation gets its name because