Gravity is what holds the planets in orbit around the sun and what keeps the moon in orbit around Earth. The gravitational pull of the moon pulls the seas towards it, causing the ocean tides. Gravity creates stars and planets by pulling together the material from which they are made.
Answer:
<h2>
d₂ = 3d</h2><h2>
The diameter of the second wire is 3 times that of the initial wire.</h2>
Explanation:
Using the formula for calculating the resistivity of an object to find the diameter.
Resistivity P = RA/L
R is the resistance of the material
A is the cross sectional area
L is the length of the material
Since A = πd²/4
P = R( πd²/4)/L
P = Rπd²/4L ... 1
If the second wire of the same material and length is found to have resistance R/9, the resistivity of the second material will be;
P₂ = (R/9)A₂/L₂
P₂ = (R/9)(πd₂²/4)/L₂
P₂ = (Rπd₂²/36)/L₂
P₂ = (Rπd₂²)/36L₂
Since the length and resistivity are the same;
P = P₂ and L =L₂
Equating 1 and 2;
Rπd²/4L = (Rπd₂²)/36L₂
Rπd²/4L = (Rπd₂²)/36L
d² = d₂²/9
d₂² = 9d²
Taking the square root of both sides;
√d₂² = √9d²
d₂ = 3d
Therefore the diameter of the second wire is 3 times that of the initial wire
Answer:
D. all sounds are caused by vibrations
Explanation:
The quantity of heat must be removed is 1600 cal or 1,6 kcal.
<h3>Explanation : </h3>
From the question we will know if the condition of ice is at the latent point. So, the heat level not affect the temperature, but it can change the object existence. So, for the formula we can use.
If :
- Q = heat of latent (cal or J )
- m = mass of the thing (g or kg)
- L = latent coefficient (cal/g or J/kg)
<h3>Steps : </h3>
If :
- m = mass of water = 20 g => its easier if we use kal/g°C
- L = latent coefficient = 80 cal/g
Q = ... ?
Answer :
So, the quantity of heat must be removed is 1600 cal or 1,6 kcal.
<u>Subject : Physics </u>
<u>Subject : Physics Keyword : Heat of latent</u>
