I need help with this !!

Heena wants to measure the volume of a ball that is 24 cm across. how should she set up her equation?

Calculate the mass of an object that has a momentum of 100kg x m/sec and velocity of 4 m/sec

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).