Answer:
15.8 V
Explanation:
The relationship between capacitance and potential difference across a capacitor is:
[tex]q=CV[/tex]
where
q is the charge stored on the capacitor
C is the capacitance
V is the potential difference
Here we call C and V the initial capacitance and potential difference across the capacitor, so that the initial charge stored is q.
Later, a dielectric material is inserted between the two plates, so the capacitance changes according to
[tex]C'=kC[/tex]
where k is the dielectric constant of the material. As a result, the potential difference will change (V'). Since the charge stored by the capacitor remains constant,
[tex]q=C'V'[/tex]
So we can combine the two equations:
[tex]CV=CV'\\CV=(kC)V'\\V'=\frac{V}{k}[/tex]
and since we have
V = 71.0 V
k = 4.50
We find the new potential difference:
[tex]V'=\frac{71.0}{4.50}=15.8 V[/tex]