A car starts from rest and after 7.0 seconds it is moving at 42 m/s. What is the car's average acceleration?

What property is a characteristic of a substance that can be observed and does not change the identity of the substance

Air initially at 0.75 bar, 1000 k, and occupying a volume of 0.12 m^3 undergoes two processes. process 1-2: the air is compressed isothermally until the volume is halved. process 2-3: the air undergoes a constant pressure process until the volume is halved again. assume ideal gas behavior. a) determine the mass of the air, in kg. b) the work and the heat transfer for each of the two processes, in kj. (100 kj = 1 bar . m^3)

Why do astronauts in the space shuttle weigh less?