Answer:
C or 3
Explanation:
A: no they are called sources of sound. A is incorrect.
B: It does. Many people attest to this. But this is not a property of physics.
C: A media is required is the correct answer.
D: Dogs might. In general we don't.
I would pick C
Answer:

Explanation:
m = Mass of object = 
mg = Weight of object = 20 N
g = Acceleration due to gravity = 
v = Final velocity = 15 m/s
u = Initial velocity = 0
d = Distance moved by the object = 150 m
= Angle of slope = 
f = Force of friction
fd = Work done against friction
The force balance of the system is

The work done against friction is
.
To be referenced, it would be true
Answer:v nxfgdjngdnmgndjfnncnfndngndsnbxzmnfn
Explanation: