Answer:
Sound is produced when an object vibrates, creating a pressure wave.
Explanation:
This pressure wave causes particles in the surrounding medium (air, water, or solid) to have vibrational motion. ... The human ear detects sound waves when vibrating air particles vibrate small parts within the ear.
The second ball should strike at double the original t value
Answer:
4v/3
Explanation:
Assume elastic collision by the law of momentum conservation:

where v is the original speed of car 1, v1 is the final speed of car 1 and v2 is final speed of car 2. m1 and m2 are masses of car 1 and car 2, respectively
Substitute 

Divide both side by
, then multiply by 6 we have



So the final speed of the second car is 4/3 of the first car original speed
Answer:
D
Explanation:
transparent_objects that allows light to pass through and can you see through them
The conservation of the mass of fluid through two sections (be they A1 and A2) of a conduit (pipe) or current tube establishes that the mass that enters is equal to the mass that exits. Mathematically the input flow must be the same as the output flow,

The definition of flow is given by

Where
V = Velocity
A = Area
The units of the flow of flow are cubic meters per second, that is to say that if there is a continuity, the volume of input must be the same as that of output, what changes if the sections are modified are the proportions of speed.
In this way

