(a) What is its resistance? Express your answer to two significant figures and include the appropriate units."
(b) How much charge passes through it in 11 min ? Express your answer to two significant figures and include the appropriate units.
Solution
(a) We can calculate the resistance by using Ohm's law:
[tex]\Delta V= I R[/tex]
Since we know that [tex]\Delta V=120 V[/tex] and [tex]I=14.5 A[/tex], we can find R:
[tex]R= \frac{\Delta V}{I} = \frac{120 V}{14.5 A}=8.3 \Omega [/tex]
(b) The current is equal to the quantity of charge by unit of time:
[tex]I= \frac{Q}{t} [/tex]
In our problem, t=11min=660 s, so we can calculate the charge passed through the hair dryer:
[tex]Q=It=14.5 A \cdot 660 s = 9570 C[/tex]
