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A rocket's required mass ratio as a function of effective exhaust velocity ratio. The classical rocket equation, or ideal rocket equation is a mathematical equation that describes the motion of vehicles that follow the basic principle of a rocket: a device that can apply acceleration to itself using thrust by expelling part of its mass with high velocity and can thereby move due to the ...
The value of the magnitude of an object's four-velocity, i.e. the quantity obtained by applying the metric tensor g to the four-velocity U, that is ‖ U ‖ 2 = U ⋅ U = g μν U ν U μ, is always equal to ±c 2, where c is the speed of light. Whether the plus or minus sign applies depends on the choice of metric signature.
Relativistic rocket means any spacecraft that travels close enough to light speed for relativistic effects to become significant. The meaning of "significant" is a matter of context, but often a threshold velocity of 30% to 50% of the speed of light (0.3c to 0.5c) is used.
Given that in general for a closed system with generalized coordinates q i and canonical momenta p i, [3] = =, = =, it is immediate (recalling x 0 = ct, x 1 = x, x 2 = y, x 3 = z and x 0 = −x 0, x 1 = x 1, x 2 = x 2, x 3 = x 3 in the present metric convention) that = = (,) is a covariant four-vector with the three-vector part being the ...
"According to the special theory the thread must contract with respect to S because it has a velocity with respect to S. However, since the rockets maintain a constant distance apart with respect to S, the thread (which we have assumed to be taut at the start) cannot contract: therefore a stress must form until for high enough velocities the ...
A space vehicle's flight is determined by application of Newton's second law of motion: =, where F is the vector sum of all forces exerted on the vehicle, m is its current mass, and a is the acceleration vector, the instantaneous rate of change of velocity (v), which in turn is the instantaneous rate of change of displacement.
SEOUL (Reuters) -One of the stages of North Korea's satellite launch rocket exploded after separation on Tuesday, video captured by an South Korean astronomy observatory showed, in what some ...
The International Space Station has an orbital period of 91.74 minutes (5504 s), hence by Kepler's Third Law the semi-major axis of its orbit is 6,738 km. [citation needed] The specific orbital energy associated with this orbit is −29.6 MJ/kg: the potential energy is −59.2 MJ/kg, and the kinetic energy 29.6 MJ/kg.