Answer:
Explanation:
You have that a parallel plate capacitor has a total energy of E when the distance between the plates is d and the charge on each plate is Q.
You take into account the following formula for the stored energy in the capacitor:
(1)
The capacitance C of the parallel plate capacitor is given by the following formula is:
(2)
A: area of the plates
ε0: dielectric permittivity of vacuum
You replace the expression (2) into the equation (1):
(3)
the previous formula is the expression for the total energy stored for the given parameters A, d and Q.
If the distance between the plates is twice and it is required that the energy is three times the initial energy, to find the value of the charge you use the equation (3):
(4)
d' = 2d
E' = 3E
Q': required charge
You replace the values of d' and E' in the equation (4) and then divide the result with the equation (3):
Finally, you solve for Q':
Then, the required charge is √6Q , to obtain three times the initial energy E, when the distance between plates is doubled.
As more resistors are added in parallel across a constant voltage source, there are more paths for current to take. So more current dribbles out of the source, and the total current supplied by the source increases.
The power supplied by the battery is (voltage) x (current). So if the voltage is constant and the current increases, the power being supplied must also increase.
<em>choice-c</em>
Answer:
0.3 seconds approximately
Explanation:
Given that the height of the building is 55.9 m and cement block accidentally falls from rest from the edge of a 55.9-m-high building. The initial velocity of the block will be equal to zero. The final velocity will be achieved by using the formula:
V^2 = U^2 + 2gH
Where g = 9.8 m/s^2
H = 55.9m
V^2 = 0 + 2 × 9.8 × 55.9
V^2 = 1095.64
V = sqrt(1095.64)
V = 33.1 m/s
The velocity When the block is 11.2 m above the ground will be 33.1 m/s and the height h = 11.2 - 1.7 = 9.5 m
The time of escape can be calculated by using the formula;
h = Ut + 1/2gt^2
9.5 = 33.1t + 1/2 × 9.8 × t^2
9.5 = 33.1t + 4.9t^2
4.9t^2 + 33.1t - 9.5
By using quadratic formula to calculate the time, the negative value is ignored and the positive values will be the time the man has to get out of the way.
Please find the attached file for the remaining solution.
The units of his measurement is newtons.
Answer: D. 102m
Explanation: Because if you subtract 67m-16m=51. 51 +51 is 102m