It could be warmer solid, or liquid, or gas, depending on the pressure and the amount of heat added.
A unit of measurement expressing the intensity of a sound of power of an electrical sound
<span>Answer:
Using 1/f = 1/d' + 1/d ...(where d' object distance and d is image distance)
1/4 = 1/7 + 1/d
1/4 - 1/7 = 1/d
3/28 = 1/d
d = 28/3
d = 9.33 cm</span>
Answer:
σ =4.180×10^{-9} C/m^2
Explanation:
electric field due to non conducting sheet is
![E=\frac{\sigma}{2\epsilon_0}](https://tex.z-dn.net/?f=E%3D%5Cfrac%7B%5Csigma%7D%7B2%5Cepsilon_0%7D)
the force acting on the piece of Styrofoam
Eq= mg
⇒E= mg/q
now,
![\frac{mg}{q} = \frac{\sigma}{2\epsilon_0}](https://tex.z-dn.net/?f=%5Cfrac%7Bmg%7D%7Bq%7D%20%3D%20%5Cfrac%7B%5Csigma%7D%7B2%5Cepsilon_0%7D)
⇒![\sigma= \frac{2mg\epsilon_0}{q}](https://tex.z-dn.net/?f=%5Csigma%3D%20%5Cfrac%7B2mg%5Cepsilon_0%7D%7Bq%7D)
![\sigma= \frac{2\times0.013\times9.81\times8.85\times10^{-12}}{5.40\times10^{-4}}](https://tex.z-dn.net/?f=%5Csigma%3D%20%5Cfrac%7B2%5Ctimes0.013%5Ctimes9.81%5Ctimes8.85%5Ctimes10%5E%7B-12%7D%7D%7B5.40%5Ctimes10%5E%7B-4%7D%7D)
charge per unit area (in C/m2) on the plastic sheet σ =4.180×10^{-9} C/m^2