What two motions combine to produce an orbit

When a book falls from a shelf to the ground without anyone pushing on it, no work is done on the book. true or false

Compare the horizontal displacement of the two balls as they travel to the ground. what do you observe?

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).