The closer the particles, the more will be the propogation of sound waves. Room contains air molecules which are far away from each other. So it takes much time for one molecule of air to disturb the other one. But in case of solids, as particles are much closer(compared to fluids), disturbance generated by one molecule is quickly transmitted to the next molecule
This is called the Phi Phenomenon.
This is an illusion of movement created when two or more adjacent lights blink on and off in quick succession; when two adjacent stationary lights blink on and off in quick succession; we perceive a single light moving back and forth between them. It is an optical illusion of perceiving a series of still images, when viewed in rapid succession, as continuous motion.
None of the choices is correct.
If two runners take the same amount of time to run a mile,
they have the same average speed. But their velocities
are not the same unless both runners begin and end their
run at the same points.
Speed is (distance covered) divided by (time to cover the distance).
Velocity is not. It's something different.
'Velocity' is not just a bigger word for 'speed'.
