David W. answered • 06/06/15
Tutor
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Hi Melissa,
Using science problems to practice math is quite practical. Be sure to get a good general understanding of the terms and you can do the math.
A watt (abbreviated W, and is joules per second) is a unit of power (it’s how my electric company computes how much to charge me each month; they use kilowatt-hours). “A watt is used to specify the rate at which electrical energy is dissipated, or the rate at which electromagnetic energy is radiated, absorbed, or dissipated.” A watt is a rate much like miles per hour is a rate (to get miles, we have to multiply by hours). My electric company charges me for kilowatt -hours used.
The problem mentions a 10-watt bulb and a 5-watt CFL (Compact Fluorescent Lamp) bulb. In recent years, CFL’s have become very popular because they produce more light per watt of power and they last longer than older-style incandescent light bulbs.
O.K., that means that a 10-watt bulb uses twice as much energy (electrical power) in an hour than a 5-watt bulb does. It also uses 5 watts more than a 5 watt bulb.
Oh, the math is now so very easy:
10 watt-hours = 2*5 watt-hours, and
10 watt-hours = 5 watt-hours + 5 watt-hours = CFL + 5 watt-hours
Be sure to understand the terms !
Using science problems to practice math is quite practical. Be sure to get a good general understanding of the terms and you can do the math.
A watt (abbreviated W, and is joules per second) is a unit of power (it’s how my electric company computes how much to charge me each month; they use kilowatt-hours). “A watt is used to specify the rate at which electrical energy is dissipated, or the rate at which electromagnetic energy is radiated, absorbed, or dissipated.” A watt is a rate much like miles per hour is a rate (to get miles, we have to multiply by hours). My electric company charges me for kilowatt -hours used.
The problem mentions a 10-watt bulb and a 5-watt CFL (Compact Fluorescent Lamp) bulb. In recent years, CFL’s have become very popular because they produce more light per watt of power and they last longer than older-style incandescent light bulbs.
O.K., that means that a 10-watt bulb uses twice as much energy (electrical power) in an hour than a 5-watt bulb does. It also uses 5 watts more than a 5 watt bulb.
Oh, the math is now so very easy:
10 watt-hours = 2*5 watt-hours, and
10 watt-hours = 5 watt-hours + 5 watt-hours = CFL + 5 watt-hours
Be sure to understand the terms !
