The mass of the boy is 35 kilograms. What is the force of friction that slowed him down? Use the equation for Newton’s second law, F = ma.

In an experiment, how can i change human errors? be specific.

Which of the following are appropriate acceleration units?

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).