3 ms·

No they don't, you need to divide, not multiply just like you would with every other unit. 1l of rain every day is 1l/day, not 1l * day . Which means Watt per d

No they don't, you need to divide, not multiply just like you would with every other unit. 1l of rain every day is 1l/day, not 1l * day . Which means Watt per day is J/s^2

AlienRobot 2y ago
I think a clearer example would be saying a car runs 20KM/H every day.
- gpderetta 2y ago
  On the other hand batteries energy capacity is commonly rated in Watt hour. Watt*day is a perfectly cromulent energy statement although a bit misleading.
  - Ekaros 2y ago
    Watt*day is weird, but at least unit of energy. Watts a day is not. Really common mistake in general to use kWh as a kW. Watthour is unit of energy. As watt is energy by time period. So you get back to units of energy. Technically watt/day could be change in power consumption.
spacedcowboy 2y ago
That’s changing “every day” into “per day”. Judging by the downvotes that is how people are reading it, but “specified time” of a rate-quantity is an integration, to me. Which makes it a multiply op over the time specified. If you pour out one bucket of sand every hour, and you do that for 10 hours, I expect the quantity of sand to be measured in buckets.
jijijijij 2y ago
If you want to be nitpicky about semantics, I think the only valid interpretation then is to take OP by their words and assume they meant energy transfer for 24h, since they did not write "per day" as you suggest: "Earth gets over 170,000 terawatts of solar energy every day" = 170 PW × 1d = 170 × P(J/s) × 86.4 × ks = 170 × 10¹⁵ × (J/s) × 86.4 × 10³ × s = 14.6 × 10²¹ × J = 14.6 ZJ However, I also think "of solar energy" could be read as specifying the type of energy for the "rate of energy transfer", which is already implied in 'watt'. And since it's related to energy usage (rate), there really is no need to leave the "rate of energy transfer" interpretation at all and get hung up on "energy vs. power": "Earth receives 170 petawatts as solar energy - 10,000 times the energy humanity uses, at any moment. Edit: And let's be real, we all only feel very smart here because we just watched the latest Technology Connections video https://www.youtube-nocookie.com/embed/OOK5xkFijPc https://www.youtube-nocookie.com/embed/OOK5xkFijPc :D

No they don't, you need to divide, not multiply just like you would with every other unit. 1l of rain every day is 1l/day, not 1l * day . Which means Watt per day is J/s^2

AlienRobot 2y ago

I think a clearer example would be saying a car runs 20KM/H every day.

gpderetta 2y ago
On the other hand batteries energy capacity is commonly rated in Watt hour. Watt*day is a perfectly cromulent energy statement although a bit misleading.
- Ekaros 2y ago
  Watt*day is weird, but at least unit of energy. Watts a day is not. Really common mistake in general to use kWh as a kW. Watthour is unit of energy. As watt is energy by time period. So you get back to units of energy. Technically watt/day could be change in power consumption.

spacedcowboy 2y ago

That’s changing “every day” into “per day”. Judging by the downvotes that is how people are reading it, but “specified time” of a rate-quantity is an integration, to me. Which makes it a multiply op over the time specified. If you pour out one bucket of sand every hour, and you do that for 10 hours, I expect the quantity of sand to be measured in buckets.

jijijijij 2y ago

If you want to be nitpicky about semantics, I think the only valid interpretation then is to take OP by their words and assume they meant energy transfer for 24h, since they did not write "per day" as you suggest: "Earth gets over 170,000 terawatts of solar energy every day" = 170 PW × 1d = 170 × P(J/s) × 86.4 × ks = 170 × 10¹⁵ × (J/s) × 86.4 × 10³ × s = 14.6 × 10²¹ × J = 14.6 ZJ However, I also think "of solar energy" could be read as specifying the type of energy for the "rate of energy transfer", which is already implied in 'watt'. And since it's related to energy usage (rate), there really is no need to leave the "rate of energy transfer" interpretation at all and get hung up on "energy vs. power": "Earth receives 170 petawatts as solar energy - 10,000 times the energy humanity uses, at any moment. Edit: And let's be real, we all only feel very smart here because we just watched the latest Technology Connections video https://www.youtube-nocookie.com/embed/OOK5xkFijPc https://www.youtube-nocookie.com/embed/OOK5xkFijPc :D