Answer:
R2 = 10.31Ω
Explanation:
For two resistors in parallel you have that the equivalent resistance is:
(1)
R1 = 13 Ω
R2 = ?
The equivalent resistance of the circuit can also be calculated by using the Ohm's law:
(2)
V: emf source voltage = 23 V
I: current = 4 A
You calculate the Req by using the equation (2):

Now, you can calculate the unknown resistor R2 by using the equation (1):

hence, the resistance of the unknown resistor is 10.31Ω
2nd and third laws of energy
Answer:
U = (ε0AV^2) / 2d
Explanation:
Where C= capacitance of the capacitor
ε0= permittivity of free space
A= cross sectional area of plates
d= distance between the plates
V= potential difference
First, the capacitance of a capacitor is obtained by:
C = ε0A/d.
Starting at the formula , U= (CV^2)/2. Formula for energy stored in a capacitor
Substitute in for C:
U = (ε0A/d) * V^2 / 2
Hence:
U = (ε0AV^2) / 2d
Answer:
The acceleration is 1 cm/s^2.
Explanation:
The acceleration is defined as the rate of change of velocity.
Here, initial velocity, u = 3/1 = 3 cm/s
final velocity, v = 4/1 = 4 cm/s
time, t = 1 s
Let the acceleration is a.
Use first equation of motion
v = u + at
4 = 3 + 1 x a
a = 1 cm/s^2