Question

Einstein's first postulate (the relativity principle) states that:

	a.	the speed of light is independent of the speed of the source or observer.
	b.	the laws of physics have the same form in all inertial reference frames.
	c.	the length of an object moving relative to an observer is measured to be shorter along its direction of motion than when it is at rest.
	d.	at speeds much less than the speed of light, the relativistic formulas reduce to the old classical formulas.
	e.	the special theory of relativity deals with inertial (nonaccelerating) reference frames.
	f.	clocks moving relative to an observer are measured to run more slowly, as compared to clocks at rest.

Answer 1

Answer: Option (b) :

The first postulate of special relativity states that, all the laws of nature of physics are the same in all consistently and uniformly moving frames of reference means in all inertial frame of reference, which is a reference frame in which a body at rest remains at rest and a body in motion moves at a uniform speed in a straight line unless acted upon by an external force.
For ex: A spaceship, cannot measure its speed relative to vacant space, but only relative to other objects.