Reply To: T-shirt designers unite and take over

[Aeronaut]

Jolly Roger wrote:

… Therefore, if 10 N= 1G of acceleration, a 100-ton ship would require only 1kN for 1G. For clarity, that would be tons of mass, not earth weight. 100 metric tons of mass would still be a sizable (and hefty) 1,000 metric tons or 3,200 tons (US) weight.

I don’t understand your math. I will explain mine.

1 Newton (N) of thrust will accelerate 1 kilogram (kg) of mass by 1 meter per second per second (m/sec^2).

10 N will accelerate 1 kg by 10 m/sec^2. 1 Gravity (G) = 9.8 m/sec^2, so 10 N/kg = 1.02 G = ~1 G.

1 metric ton mass is 1,000 kg, therefore it would take ~10,000 N (10 kN) to accelerate it to 1 G.

100 metric tons mass is 100,000 kg, therefore it would take ~1,000,000 N (1 MN) to accelerate it to 1 G.

The Space Shuttle has a mass of ~20,000 metric tons. It needs ~200 MN thrust for 1 G.

Thanx for explaining it more clearly than my texts, Jolly Roger. I was “thinking” I’d seen a typo.