Car Speed for 1kW Home Power Usage

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Homework Help Overview

The problem involves calculating the speed of a car based on the kinetic energy equivalent to the energy consumed by a house over a specific time period. The subject area includes concepts of power, energy, and kinetic energy.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the relationship between power, energy, and time, with one attempting to apply the equations for power and kinetic energy. Questions arise regarding the correct interpretation of power consumption and energy units.

Discussion Status

Participants are exploring different interpretations of the power consumption statement and clarifying the equations relevant to the problem. Some guidance has been offered regarding how to calculate energy based on power and time, but no consensus has been reached on the correct approach to find the car's speed.

Contextual Notes

There is some confusion regarding the units of power and energy, particularly whether the power consumption should be expressed in terms of kilowatt-hours. The original poster's conversion of time and power is noted, but the need for further clarification on force in the context of the equations is evident.

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Homework Statement


The power consumption by a typical house is 1 kW. If the kinetic energy of a car (mass 130 kg) is equal to the total energy used by the house in 1.2 minute, what is the car’s speed?

Homework Equations


P=W/t
P=Fv
P:Power

The Attempt at a Solution


I converted 1kW to 1000 Watts and 1.2 minutes to 72 seconds and put it into the first equation but don't know how to get F for the second equation.
 
Last edited:
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Consider:

Energy = Power * time

and

Kinetic Energy = mv2/2
 
Do you mean to say that the power consumed by a typical house is 1 kWh?
 
It is better to say that the house consumes energy at the rate of 1kW. Exactly like the wattage rating on a light bulb. If the house is "on" for 1.2 minutes then you can determine the energy consumed by the house during this interval by:

Energy = Power * time
 

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