MY NOTESASK YOUR TEACHERPRACTICE ANOTHERThe big mall near Sally and Amy's city has extended their operating hours toaccommodate the huge crowds expected for the After Thanksgiving Sale. Intheir eagerness to beat the crowd, Sally forgets to turn off the headlightswhen she gets out of the car at the mall parking lot. The headlights in hercar require 45.0 w of power each, and her 12.0 V car battery is rated at92.0 A h. When the two friends come back to the car after a long andsuccessful shopping spree, they find that the car refuses to start as thebattery is now completely discharged. How long were they in the mall?Assume that they come out just as the battery dies.

The big mal near Sally and Amy's city has extended their operating hoursto accommodate the huge crowds expected for the After Thanksgiving Sale. In their eagerness to beat the crowd, Sally forgets to turn off the headlights when she gets out of the car at the mall parking lot. The headights in her car require 45.0 w of power each, and her 12.0 V car battery is rated at 92.0 A-h. When the two friends come back to the car after a long and successful shopping spree, they find that the car refuses to start as the battery is now completely discharged. How long were they in the mal? Assume that they come out just as the battery dies.

The big mal near Sally and Amy's city has extended their operating hoursto accommodate the huge crowds expected for the After Thanksgiving Sale. In their eagerness to beat the crowd, Sally forgets to turn off the headlights when she gets out of the car at the mall parking lot. The headights in her car require 45.0 w of power each, and her 12.0 V car battery is rated at 92.0 A-h. When the two friends come back to the car after a long and successful shopping spree, they find that the car refuses to start as the battery is now completely discharged. How long were they in the mal? Assume that they come out just as the battery dies.

College Physics

1st Edition

ISBN:9781938168000

Author:Paul Peter Urone, Roger Hinrichs

Publisher:Paul Peter Urone, Roger Hinrichs

Chapter21: Circuits And Dc Instruments

Section: Chapter Questions

Problem 28PE: Integrated Concepts A 12.0-V emf automobile battery has a terminal voltage of 16.0 V when being...

See similar textbooks

Similar questions

The human body can exhibit a wide range of resistances to current depending on the path of the current, contact area, and sweatiness of the skin. Suppose the resistance across the chest from the left hand to the right hand is 1.0 106 . (a) How much voltage is required to cause possible heart fibrillation in a man, which corresponds to 500 mA of direct current? (b) Why should rubber-soled shoes and rubber gloves be worn when working around electricity?
Integrated Concepts (a) Assuming 95.0% efficiency for the conversion of electrical power by the motor, what current must the 12.0-V batteries of a 750-kg electric car be able to supply: (a) To accelerate from rest to 25.0 m/s in 1.00 min? (b) To climb a 2.00 102-m- high hill in 2.00 min at a constant 25.0-m/s speed while exerting 5.00 102 N of force to overcome air resistance and friction? (c) To travel at a constant 25.0-m/s speed, exerting a 5.00 102 N force to overcome air resistance and friction? See Figure 20.44.
Integrated Concepts A light-rail commuter train draws 630 A of 650-V DC electricity when accelerating, (a) What is its power consumption rate in kilowatts? (b) How long does it take to reach 20.0 m/s stalling from rest if its loaded mass is 5.30 1()4 kg, assuming 95.0% efficiency and constant power? (c) Find its average acceleration. (d) Discuss how the acceleration you found for the light-rail train compares to what might be typical for an automobile.
An all-electric car (not a hybrid) is designed to run from a bank of 12.0-V batteries with total energy storage of age of 2.00 107J. If the electric motor draws 8.00 kW as the car moves at a steady speed of 20.0 m/s. (a) what is the current delivered to the motor? (b) How far can the car travel before it is out of juice"?
SI. A physics student has a single-occupancy dorm loom. The student lias a small refrigerator that runs with a current of 3.00 A and a voltage of 110 V, a lamp that contains a 100-YV bulb, an overhead light with a 60-W bulb, and various other small devices adding up to 3.00 W. (a) Assuming the power plant that supplies 110 V electricity to the dorm is 10 km away and the two aluminum transmission cables use 0-gauge wire with a diameter of 8.252 mm, estimate the percentage of the total power supplied by the power company that is lost in the transmission, (b) What would be the result is the power company delivered the electric power at 110 kV?
. The generator at a large power plant has an output of 1,000,000 kW at 24,000 V. (a) If it were a DC generator, what would he the current in it? (b) What is its energy output each day—in joules and in kilowatt—hours? (c) If this energy is sold at a price of 10 cents per kilowatt-hour, how much revenue does the power plant generate each day?
A Van de Graaff generator is one of the original particle accelerators and can be used to accelerate charged particles like protons or electrons. You may have seen it used to make human hair stand on end or produce large sparks. One application of the Van de Graaff generator is to create X-rays by bombarding a hard metal target with the beam. Consider a beam of protons at 1.00 keV and a current of 5.00 mA produced by the generator, (a) What is the speed of the protons? (b) How many protons are produced each second?
. A certain electric motor draws a current of 10 A when connected to 120 V (a) What is the motor’s power consumption? (b) How much energy does it use during 4 h of operation? Express the answer in joules and in kilowatt-hours.
A small office-building air conditioner operates or 408-V AC and consumes 50.0 kW. (a) What is its effective resistance? (b) What is the cost of running the air conditioner during a hot summer month when it is on 8.00 h per day for 30 days and electricity costs 9.00 cenls/kW h ?
The IR drop across a resistor means that there is a change in potential or voltage across the resistor. Is there any change in current as it passes through a resistor? Explain.
Integrated Concepts A flashing lamp in a Christmas earring is based on an RC discharge of a capacitor through its resistance. The effective duration of the flash is 0.250 s, during which it produces in average 0.500 W from an average 3.00 V. (a) What energy does it dissipate? (b) How much charge moves through the lamp? (c) Find the capacitance. (d) What is the resistance of the lamp?
A 20.00-ohm; 5.00-watt resistor is placed in series with a power supply, (a) What is the maxim tun voltage that can be applied to the resistor without hanniug the resistor? (b) What would be the current through the resistor?