Observer A sees a ruler moving by in a relativistic train and measures its length to be LA. Observer B moves together with the train and measures the length of the ruler to be LB. These two results will be such that

A) LA > LB.
B) LA = LB.
C) LA < LB.
D) LA could be greater or smaller than LB depending on the direction of the motion.


C

Physics & Space Science

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An astronaut who weighs 800 N on the surface of the Earth lifts off from planet Zuton in a space ship. The free-fall acceleration on Zuton is 3.0 m/s2 (down). At the moment of liftoff the acceleration of the space ship is 0.50 m/s2 (up). What is the magnitude of the force of the space ship on the astronaut?

A. 41 N B. 0.29 kN C. 0.24 kN D. 0.20 kN E. 0.37 kN

Physics & Space Science