Answer:
Elastic potential energy, 
Explanation:
Charge, 
Potential, V = 50 V
It is required to find the electric potential energy in a capacitor stored in it. The formula of the electric potential energy in a capacitor is given by :

So, the electric potential energy stored in the capacitor is 
Answer: R = 394.36ohm
Explanation: In a LR circuit, voltage for a resistor in function of time is given by:

ε is emf
L is indutance of inductor
R is resistance of resistor
After 4s, emf = 0.8*19, so:





R = 394.36
In this LR circuit, the resistance of the resistor is 394.36ohms.
Answer:

Explanation:
The period of a simple pendulum is given by:

where
L is the length of the pendulum
g is the acceleration of gravity
From this equation we can write

Taking the square of this equation, we get:

So we see that
is proportional to L and inversely proportional to g. So, we can write:

So the only correct option is

Answer:
Scientific theories and laws develop from the acquisition of scientific knowledge.
Explanation:
t
Use Coulomb law: F = k * q1*q2 / (r^2), where k = 9.00 * 10^9 N.m^2/C^2
F = 9.00 * 10^9 N.m^2/C^2 * 2.4*10^-8 C * 1.8*10^-6 C / [0.008m]^2 = 38.88 * 10^ -5 N
F = 39 * 10 -5N