Which of these is not a conservative force and does not have a form of potential energy connected with it?

The discovery that the universe appears to be expanding led to a widely accepted theory called a.) the big bang theory b.) the doppler effect c.) hubble’s law d.) solar nebular theory e.) the seyfert theory

True or false when elements combine to form a mixture, the resulting chemical properties may be very different from those of the elements that make it.

Consider a system to be two train cars traveling toward each other. what is the total momentum of the system before the train cars collide?   kg • what must the total momentum of the system be after the train cars collide?   kg •