To calculate the force between two negative charges, we use the formula which is given by the Coulomb`s Law as

Here,
and
are the charges on the pith balls, r is the separation between the charges and k is constant and its value is
.
Given
and
.
Substituting these values in above formula we get,

Thus, the repulsive force between two pith balls is
.
Yes all those are correct, but I don't know what the question was
1. C
2. A
3. E
4. D
5. B
6. F
i might have 2 and 6 mixed up, not completely sure tho
Answer:
<em>The amount of water in circulation is the same</em>
Explanation:
The water cycle is the pathway in which water moves from the atmosphere to the earth and back to atmosphere ones again.
During the sunny period, the temperature of the earth is heated up, water evaporates to the atmosphere as water vapour. The water vapour gathers as cloud and comes back to the earth as rain, which enters our rivers and stream. Thereby maintaining a continuous cycle.
With the water cycle, the movement of water via precipitation and evaporation is the same on earth.
Answer:
y = 2.74 m
Explanation:
The linear thermal expansion processes are described by the expression
ΔL = α L ΔT
Where α the thermal dilation constant for concrete is 12 10⁻⁶ºC⁻¹, ΔL is the length variation and ΔT the temperature variation in this case 20ªc
If the bridge is 250 m long and is covered by two sections each of them must be L = 125 m, let's calculate the variation in length
ΔL = 12 10⁻⁶ 125 20
ΔL = 3.0 10⁻² m
Let's use trigonometry to find the height
The hypotenuse Lf = 125 + 0.03 = 125.03 m
Adjacent leg L₀ = 125 m
cos θ = L₀ / Lf
θ = cos⁻¹ (L₀ / Lf)
θ = cos⁻¹ (125 / 125.03)
θ = 1,255º
We calculate the height
tan 1,255 = y / x
y = x tan 1,255
y = 125 tan 1,255
y = 2.74 m