# Determining the exit velocity from an air nozzle

Air enters a nozzle operating at steady state at 800 ºR with a negligible velocity and exits the nozzle at 570 ºR. Heat transfer occurs from the air to the surroundings at a rate of 10 Btu per pound of air flowing. Assuming ideal gas behavior and neglecting potential energy effects, determine the velocity at the exit in ft/s.

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Solution:

First, we will convert everything in SI and finally we will convert the velocity in ft/s.

Given: T1 = 800°R = 1273K

T2 = 570°R = 985.7K

q_out = 10 Btu/lb = 23.26 kJ/kg (heat lost to surroundings)

Since incoming air has a negligible velocity, it's kinetic energy is also negligible (that means the total enthalpy is equal to the static one).

If no heat losses would occur, the kinetic ...

#### Solution Summary

This solution provides a detailed written and formulaic explanation on how to determine the exit velocity of air leaving a nozzle, in ft/s.