Astronomers believe that cosmic background radiation formed:
a. about 1 billion years ago.
b. about 1 million years ago.
c. shortly after the big bang.
d. about 100,000 years ago.

John throws .4 kg ball with velocity of 18 m/s. hits .2 kg bottle and bottle flies 25 m/s. how fast is ball traveling after hitting the bottle?

What is the power rating of the lightbulb if 3.0 a flow through it when connected to a 15 v battery

Refrigerant-134a flows through a carnot heat pump cycle at 0.5 kg/s. it is known that the maximum absolute temperature in the cycle is 1.1 times the minimum absolute temperature, and the net power input to the cycle is 2.5 kw. if the refrigerant changes from a saturated vapor to a saturated liquid during the heat rejection process, determine the maximum magnitude of the enthalpy of vaporization for this process in kj/kg (with 3 significant figures).