Answer:
This is false.
Explanation:
Heat rash develops when some of your sweat ducts clog. Instead of evaporating, perspiration gets trapped beneath the skin, causing inflammation and rash. Heat rash is usually self-limited, meaning it resolves on its own without treatment. Over-the-counter treatments such as calamine, hydrocortisone cream, itch preparations (such as Benadryl spray), or sunburn lotions can be used as skincare to treat the itching and burning symptoms. Heat rash usually goes away on its own within three or four days so long as you don't irritate the site further. Heat rash happens when the sweat glands get blocked. The trapped sweat irritates the skin and leads to small bumps.
<em>A statement that is true for ALL of the examples of electromagnetic waves is that;</em>
A) They all move at the same speed in a vacuum
<u>The reason for qualifying 'in vacuum' is because EM waves of different frequencies often propagate at different speeds through material. Generally speaking, we say that light travels in waves, and all electromagnetic radiation travels at the same speed which is about 3.0 * 108 meters per second through a vacuum.</u>
Answer:
As the concentration of a solute in a solution increases, the freezing point of the solution <u><em>decrease </em></u>and the vapor pressure of the solution <em><u>decrease </u></em>.
Explanation:
Depression in freezing point :
where,
=depression in freezing point =
= freezing point constant
m = molality ( moles per kg of solvent) of the solution
As we can see that from the formula that higher the molality of the solution is directly proportionate to the depression in freezing point which means that:
- If molality of the solution in high the depression in freezing point of the solution will be more.
- If molality of the solution in low the depression in freezing point of teh solution will be lower .
Relative lowering in vapor pressure of the solution is given by :
= Vapor pressure of pure solvent
= Vapor pressure of solution
= Mole fraction of solute
Vapor pressure of the solution is inversely proportional to the mole fraction of solute.
- Higher the concentration of solute more will the be solute's mole fraction and decrease in vapor pressure of the solution will be observed.
- lower the concentration of solute more will the be solute's mole fraction and increase in vapor pressure of the solution will be observed.
Answer:
25000 V
Explanation:
The formula for potential is
V = Kq/r
Potential at B due to the charge placed at origin O
V1 = K q / OB
V1 = 10000 V
Potential at B due to the charge placed at A
V2 = K q / AB
V2 = 15000 V
Total potential at B
V = V1 + V2 = 10000 + 15000 = 25000 V
Answer:
Explanation:
The angular momentum of electron mvR = 6 x 10⁻²⁵ Js
Magnetic field B = 2.5 x 10⁻³ T
radius of circular path R = mv / Bq
where m is mass , v is velocity and q is charge on electron
R² = mvR / Bq
R² = 6 x 10⁻²⁵ / 2.5 x 10⁻³ x 1.6 x 10⁻¹⁹
= 1.5 x 10⁻³
R = 3.87 x 10⁻² m
mvR = 6 x 10⁻²⁵
v = 6 x 10⁻²⁵ / mR
= 6 x 10⁻²⁵ / 9.1 x 10⁻³¹ x 3.87 x 10⁻²
= .17 x 10⁸
= 17 x 10⁶ m/s
