Thermodynamics Basic principles, concept and definitions

Question

Using local g = 9.807 m/s^2, and that its variation is -0.003 ft/s^2 per 1000 ft ascent. Find the height in meters where the weight of a given man is reduced by 0.3%

Answer 1

Weight = mg

W_f = 99.7% of W

W_f = 0.997W

or .997g because mass does not change, only gravity does.

.997(9.807) = 9.776 m/s²

9.807 - 9.776 = 0.031 m/s²

convert 0.003 ft/s² into m/s²

0.003ft * 1m/3.2808ft = 0.000914 m

0.031 m/s² / 0.000914 m/s² per 1000ft ascent = 3.15 x 1000ft of ascent

The ascent would be approximately 3150 feet until the man lost 0.3% of his weight.