Question

Which of the following is the correct formula for STE?

(a) Es=\(\Big\{H-\frac{V^2}{2g}\Big\}\)

(b) Es=\(\Big\{H+\frac{V^2}{g}\Big\}\)

(c) Es=\(\Big\{H+\frac{V^2}{2}\Big\}\)

(d) Es=\(\Big\{H+\frac{V^2}{2g}\Big\}\)

I had been asked this question during an interview.

This intriguing question comes from High Performance Climb in division Climb and Descent Performance of Aircraft Performance

Answer 1

Correct option is (d) Es=\(\Big\{H+\frac{V^2}{2g}\Big\}\)

For explanation I would say: The correct formula for specific total energy is given by the formula Es=\(\Big\{H+\frac{V^2}{2g}\Big\}\) where ‘Es’ is specific total energy, ‘H’ is height, ‘V’ is velocity and ‘g’ is acceleration due to gravity. Specific total energy is the potential and kinetic energy per unit mass. This is few times referred as the energy height as it represents the height of the aircraft would attain if all the kinetic energy is converted to potential energy.