The lens of a telescope has a diameter of 25 cm. You are using it to look at two stars that are 2 × 1017 m away from you and 6 × 109 m from each other. You are measuring light with a wavelength of 700 nm. As the light goes through the lens, it diffracts. a. Is it possible, using this telescope, to see the two stars as separate stars? b. What is the minimum possible lens diameter you would need in order to resolve these two stars?

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).