Answer:
C. undulating displacement of air molecules caused by pressure changes.
Explanation:
Sound is a mechanical wave arising from the movement back and forth of the media objects through which the sound wave travels.If a sound wave moves through air from left to right, then particles of air will move both to the right and to the left as the sound wave's energy passes through it.
The sound wave is formed by air molecules that are displaced due to pressure changes.
Therefore the answer is C.
After the crash the momentum before the crash is equal to the momentum after the crash
Answer:
When two substances are mixed together, a color change is observed. This observation is not enough evidence that there is a chemical reaction happening because color changes are not indicators of chemical reaction:
Answer:
Final energy = Uf = initial energy × d₂/d₁
Explanation:
Energy is the ability to do work.
capacitor is an electronic device that store charges
where
V is the potential difference
d is the distance of seperation between the two plates
ε₀ is the dielectric constant of the material used in seperating the two plates, e.g., paper, mica, glass etc.
A = cross sectional area
U =¹/₂CV²
C =ε₀A/d
C × d=ε₀A=constant
C₂d₂=C₁d₁
C₂=C₁d₁/d₂
charge will 'q' remains same in the capacitor, if the capacitor was disconnected from the electric potential source (v) before the separation of the plates was replaced
Energy=U =(1/2)q²/C
U₂C₂ = U₁C₁
U₂ =U₁C₁ /C₂
U₂ =U₁d₂/d₁
Final energy = Uf = initial energy × d₂/d₁
The answer is D: all electromagnetic waves can travel in a vacuum
