System a and system b are each in thermal equilibrium with system c. according to the zeroth law of thermodynamics, systems a and b must be separated by an insulator
in contact with a source of heat
at different temperatures
in thermal equilibrium with each other

Can somebody explain to me how newton's 3rd law relates to momentum? ~ap physics 1

15. give an example for some particles or waves that are moving faster than light in everyday life 16. what is a laser? 17. what is an oscilloscope? 18. what does it means practically that nothing is faster than light in vacuum? 19. what is vacuum?

Ahot-air balloonist, rising vertically with a constant speed of 5.00 m/s releases a sandbag at the instant the balloon is 40.0 m above the ground. after it is released, the sandbag encounters no appreciable air drag. compute the velocity of the sandbag at 0.250 s after its release.