The sum of angles in a regular pentagon is
180*(5 - 2) = 540°
Each internal angle is 540/5 = 108°.
Each vertex creates a line of symmetry to the midpoint of the opposite side,
as shown in the figure.
Answer: 5 lines of symmetry.
Answer:
16 times as strong
Explanation:
From the question given above, the following assumptions were made:
Initial Force (F₁) = F
Initial distance apart (r₁) = r
Final distance apart (r₂) = ¼r
Final force (F₂) =?
Next, we shall obtain a relationship between the force and the distance apart. This can be obtained as follow:
F = GM₁M₂ / r²
Cross multiply
Fr² = GM₁M₂
If G, M₁ and M₂ are kept constant, then,
F₁r₁² = F₂r₂²
Finally, we determine the new force as follow:
Initial Force (F₁) = F
Initial distance apart (r₁) = r
Final distance apart (r₂) = ¼r
Final force (F₂) =?
Fr² = F₂ × (¼r)²
Fr² = F₂ × r²/16
Fr² = F₂r² / 16
Cross multiply
16Fr² = F₂r²
Divide both side by r²
F₂ = 16Fr² / r²
F₂ = 16F
From the calculations made above, we can see that the new force is 16 times the original force.
Thus, the new force is 16 times stronger.
Answer:
(b) the point charge is moved outside the sphere
Explanation:
Gauss' Law states that the electric flux of a closed surface is equal to the enclosed charge divided by permittivity of the medium.

According to this law, any charge outside the surface has no effect at all. Therefore (a) is not correct.
If the point charge is moved off the center, the points on the surface close to the charge will have higher flux and the points further away from the charge will have lesser flux. But as a result, the total flux will not change, because the enclosed charge is the same.
Therefore, (c) and (d) is not correct, because the enclosed charge is unchanged.
Answer:
The correct answer is part 'c' 160 dB
Explanation:
When noise levels of different intensities are superimposed the resultant intensity is given by the equation

where,
is the intensity of a general sound level
Since we have 10000 fans each producing sound of 80dB thus the resultant intensity is given using the above formula as

