|MadSci Network: Physics|
Hi there! The short answer is that the acceleration felt onboard the spaceship (your artificial gravity) will always equal the acceleration of the spaceship. This is independent of the velocity of the ship. (Velocity and acceleration are different things). For example, there's only a microgravity environment - sometimes called wieghtlessness - in the space shuttle once it's safely in orbit, even though it's travelling at nearly 8 kilometres a second - here, no rocket acceleration means no "artificial gravity". The slightly longer answer: Isaac Newton realised that force is proportional to the rate of change of momentum. In simple terms, F = m * a Where "F" is the force, "m" the mass and "a" the acceleration. You can see from this equation that the acceleration will rise if the mass falls and/or the force rises. For chemical rockets, where the mass of the spaceship is mostly fuel and oxidiser, the fall in the mass is quite dramatic, and the rise in the acceleration is high. In the shuttle's case, just before it enters orbit, given that the three main engines can produce about 2278000 newtons in a vaccuum, and the mass of the shuttle is around 105000kg, coupled to an empty external tank mass of 26600kg (NASA figures), the equation is: F = m * a 3*2278000 = (105000+26600) * a a = 51.9 metres per second squared Since 1 Earth gravity is 9.8 metres per second squared, the shuttle astronauts would be subjected to over 5g of acceleration. This is deemed too much the crew, so in reality the shuttle enters orbit with some residual fuel left in the tank (thereby increasing its mass) and with the engines throttled back to maintain around 3 gravities. I hope this helps answer your question! Andy Goddard
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