Answer: When a liquid or gas is heated, the molecules move faster, bump into each other, and spread apart. Because the molecules are spread apart, they take up more space. ... The molecules move more slowly and take up less space. Therefore temperature can affect density.
Explanation:
W work
F force
s distance
If F = constant:
W₁ = F·s
If you triple the force and the distance:
W₂ = 3F · 3s = 9 F·s = 9 W₁
If the cross-section of a wire of fixed length is doubled, the resistance of that wire change into doubled.We know that <span>the total </span>length<span> of the wires will </span>affect<span> the amount of </span>resistance. <span> The longer the wire, the more </span>resistance<span> that there will be so the answer is doubled.</span>
When the capacitor is connected to the voltage, a charge Q is stored on its plates. Calling 
the capacitance of the capacitor in air, the charge Q, the capacitance and the voltage (
) are related by
(1)
when the source is disconnected the charge Q remains on the capacitor.
When the space between the plates is filled with mica, the capacitance of the capacitor increases by a factor 5.4 (the permittivity of the mica compared to that of the air):
this is the new capacitance. Since the charge Q on the plates remains the same, by using eq. (1) we can find the new voltage across the capacitor:
And since 
, substituting into the previous equation, we find:
Ohm's law states that V = IR
87 = 2 x R
R = 87/2 ohms
Hope this helps :)
