Answer:

Explanation:
given,
velocity of particle 1 = 0.741 c to left
velocity of second particle = 0.543 c to right
relative velocity between the particle = ?
for the relative velocity calculation we have formula

u_x = 0.543 c
v_x = - 0.741 c




Relative velocity of the particle is 
means that a body is in motion, and its velocity is measured in meters per second. And, that velocity is increasing by two meters per second, every second.
Answer:
physical
Explanation:
how thick something is is a physical trait, so it's a physical property!
Answer:
Newtons first law
Explanation:
object in rest stays at rest
object in motion stays in motion