Examples of Sounds Example: siren
Uses of the Sound
A siren announces the approaching of an
ambulance
1. radio
2. church bells ringing
3. knocking at the door
4. fire truck siren
5. blowing of horn​

Imagine you are riding on a yacht in the ocean and traveling at 20 mph. you then hit a golf ball at 100 mph from the deck of the yacht. you see the ball move away from you at 100mph, while a person standing on a near by beach would observe your golf ball traveling at 120 mph (20 mph + 100 mph). now imagine you are aboard the hermes spacecraft traveling at 0.1c (1/10 the speed of light) past mars and shine a laser from the front of the ship. you would see the light traveling at c (the speed of light) away from your ship. according to einstein’s special relativity, how fast will a person on mars observe the light to be traveling? a) 0.1c (1/10 the speed of light) b) c (the speed of light) c)1.1c (c+0.1c)

Often called simply "velocity," this is the velocity of an object at a particular moment in time.

What happens when a rubber rod is rubbed with a piece of fur?