Final answer:
In the given scenario with reference frames s and s' moving toward each other at 3c/4, an object moving at 3c/4 in the s frame has a velocity of 0 when measured from the s' frame due to the relativistic velocity addition formula.
Step-by-step explanation:
The question is about calculating the velocity of an object as measured from a different reference frame in relativistic mechanics. In this scenario, reference frames s and s' are moving towards each other with relative velocity 3c/4, and an object in frame s is moving with velocity 3c/4 towards s. To find the velocity of the object as measured from frame s', we use the relativistic velocity addition formula:
u' = (u + v) / (1 + (uv/c2))
Substituting the given values, we have:
u' = ((3c/4) + (-3c/4)) / (1 + ((3c/4)(-3c/4)/c2))
After simplification:
u' = 0 / (1 - (9/16))
u' = 0 / (7/16)
u' = 0 (since the numerator is 0)
Thus, the object appears to be stationary (velocity of 0) from frame s' because the numerator of the relativistic formula is zero due to opposite velocities cancelling each other out.