10 points for first answer- physics help needed?

7. A 24 W resistor is used to control the speed of a vacuum cleaner plugged in to a 110 V circuit. If 90 V of energy is lost in the resistor, determine (a) the voltage left to run the vacuum cleaner, and (b) the current flowing through the resistor.

8. When a toaster is plugged into a 120 V outlet it draws 8.0 A of current. Determine the total resistance of the toaster.

9. Determine the electrical resistance of a clothes dryer that is plugged into a 240 V outlet and draws 18 A of current.

10. When you make a telephone call the electrical signal created by your voice travels down telephone wires, which typically have a resistance of approximately 250 W. Calculate the current flowing in the telephone wires assuming that your phone generates a voltage of 9.5 V.

I think all these questions can be solved using Ohm's law, V=IR, where V is voltage, I is current (amps), and R is resistance (usually measured in Ohms).

For question 7, if I understand it correctly, there is a voltage drop of 90 V across the resistor and a drop of 110V-90V=20V across the rest of the circuit. Using Ohm's law, the current through the resistor can be found by dividing 90V by the resistance (24 W?)

The rest of the questions can be solved with Ohm's law. Current, I, is equal to V divided by R, and resistance is V divided by I.