Question

The energy change is given by __________

(a) ΔE=\(\frac{T^2}{S^2}\)

(b) ΔE=\(\frac{T^2}{S}\)

(c) ΔE=\(\frac{T}{S}\)

(d) ΔE=T x S

This question was posed to me in unit test.

My enquiry is from Estimation of Take-off Distances in division Take-off and Landing Performance of Aircraft Performance

Answer 1

Right choice is (c) ΔE=\(\frac{T}{S}\)

For explanation I would say: The energy change is given by ΔE=excess thrust x distance moved i.e. ΔE=T x S where T is excess thrust and S is distance moved. This energy chance happens when the aircraft is undergoing an airborne phase.