Which of the following is the law of conservation of momentum?

a. the impulse acting on any object is the change in momentum that it causes.
b. the acceleration of any object is equal to the net force acting on it divided by its mass.
c. in the absence of any external force, the total momentum of a system stays the same.
d. when two objects interact within a closed system, neither one changes its momentum.

Explain the consequences of this addiction to the brain tissue

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)

Give one example to show that when substances are mixed,it may result in a chemical or a physical change depending on the conditions.