For every hour how much would 75 watt bulb cost for the energy. Also how much energy would a 50 watt bulb use and how much would it cost per hour.
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Remember the motto:
Power is to energy as speed is to distance.
Power is a RATE. Energy is an entity.
Power is the RATE at which energy is put to use. Energy is the cumulative total of all power, throughout a period of operation of interest.
BY DEFINITION, the wattage rating on a bulb *is* the power that it is expected to consume. That is the rate at which it uses energy. It might be more or less, depending on subtle conditions causing error, but in general the power is equal to the rated value. For light bulbs, it is important to know that the power ratings are only valid when the proper RMS voltage is across the terminals.
I cannot answer you how much energy the bulbs consume, unless you tell me how much time you operate them.
I can indeed tell you the cost per time unit, but I do also need to know the going price of energy for your utility. Since you didn't tell me, I will assume $0.15 per kilowatt-hour.
Important: what is a kilowatt-hour?
Hint: it is NOT a "kilowatt per hour". Watts and kilowatts already have the "per time unit" embedded in them.
The dash is unpronounced, and what it means is multiplication. A kilowatt-hour takes the power unit of kilowatts, multiplies it by an hour to kill the denominator's time unit, and as such makes it an energy unit.
A 1000 Watt device operated continuously for an hour consumes 1 kW-hr of energy, by definition.
These bulbs are less than 1 kW. A 75W bulb is 0.075 kW, and thus for every hour, it consumes 0.075 kW-hr of energy. This yields a cost rate of $0.01125 per hour, not very much at all. But it of course adds up with lifetimes of usage.
Answer for a 50 W bulb:
$0.0075 per hour
Power is to energy as speed is to distance.
Power is a RATE. Energy is an entity.
Power is the RATE at which energy is put to use. Energy is the cumulative total of all power, throughout a period of operation of interest.
BY DEFINITION, the wattage rating on a bulb *is* the power that it is expected to consume. That is the rate at which it uses energy. It might be more or less, depending on subtle conditions causing error, but in general the power is equal to the rated value. For light bulbs, it is important to know that the power ratings are only valid when the proper RMS voltage is across the terminals.
I cannot answer you how much energy the bulbs consume, unless you tell me how much time you operate them.
I can indeed tell you the cost per time unit, but I do also need to know the going price of energy for your utility. Since you didn't tell me, I will assume $0.15 per kilowatt-hour.
Important: what is a kilowatt-hour?
Hint: it is NOT a "kilowatt per hour". Watts and kilowatts already have the "per time unit" embedded in them.
The dash is unpronounced, and what it means is multiplication. A kilowatt-hour takes the power unit of kilowatts, multiplies it by an hour to kill the denominator's time unit, and as such makes it an energy unit.
A 1000 Watt device operated continuously for an hour consumes 1 kW-hr of energy, by definition.
These bulbs are less than 1 kW. A 75W bulb is 0.075 kW, and thus for every hour, it consumes 0.075 kW-hr of energy. This yields a cost rate of $0.01125 per hour, not very much at all. But it of course adds up with lifetimes of usage.
Answer for a 50 W bulb:
$0.0075 per hour
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Watt is a unit of power. Power is defined as energy/time. So the watt is Joules/Second. So if you left a 75 watt lightbulb on for a second, you would use 75 joules of energy. Energy is billed in Watt-hours. In other words, they take the watts you use and multiply it by the hours you use those watts. I believe a typical number is 11 cents a kilowatt hour. So if you left a 75 watt lightbulb on for one hour, you would use 75 watt-hours, or .075 kilwatt hours, or about one cent.
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about 75 watts
k seriously, in my neck of the woods, a kwh is less than 10¢.
a 75 watt bulb wont reach 1kw in an hour (75w/h)
do the math.
k seriously, in my neck of the woods, a kwh is less than 10¢.
a 75 watt bulb wont reach 1kw in an hour (75w/h)
do the math.