No, Friction was not Negligible. If you push a block on a surface, it will not continue to move unless you are still pushing it.
This point is called the epicenter. The epicenter is important when it comes to the Earth's surface, because it pinpoints where Earthquakes begin to take shape and occur. It is the place where the most damage is caused by an earthquake and is found above the hypocenter.
It's a tough question as to whether light is a wave or a particle..
The statement is FALSE. Not all types of waves need a medium to propagate. Light can travel without a medium.
Extra Information:
Light is a longitudinal wave, sound is transverse.
Longitudinal waves do not need a medium.
Transverse waves need a medium.
This is why, for example, in the vacuum of space, light travels from stars, but sound does not.
