(b) Consider a particular phone that has a battery rated at 4,000 mAh. The battery operates at a potential difference of 3.90 V. How much energy, in units of kilowatt-hours, is stored in a fully charged battery? kWh (c) If electricity costs $0.12 (or 12.0 cents) per kilowatt-hour, what is the value of the total amount of energy stored in this battery? Express your answer in cents (or 0.01 of a dollar). ¢ (d) When the phone is idle (that is, turned on but not making calls or texts, using GPS, or running any power-hungry apps), it will operate continuously for 29.2 hours from a fully charged battery, until the battery runs out. How much average current does the phone draw while idle? Express your answer in milliamperes. mA

(b) Consider a particular phone that has a battery rated at 4,000 mAh. The battery operates at a potential difference of 3.90 V. How much energy, in units of kilowatt-hours, is stored in a fully charged battery? kWh (c) If electricity costs $0.12 (or 12.0 cents) per kilowatt-hour, what is the value of the total amount of energy stored in this battery? Express your answer in cents (or 0.01 of a dollar). ¢ (d) When the phone is idle (that is, turned on but not making calls or texts, using GPS, or running any power-hungry apps), it will operate continuously for 29.2 hours from a fully charged battery, until the battery runs out. How much average current does the phone draw while idle? Express your answer in milliamperes. mA