A.$5.0
B.$7.5
C.$10.0
C.$12.5
更新1:
Sorry...C.$12.5 should be D.... and the ans. is not D!!!
phy mc - electric energy cost
2007-04-25 3:12 am
If the electric energy costs $0.5 per kWh, find the cost of a 500W rice-cooker and a 2000W heater, each operated for 10 hours.
A.$5.0
B.$7.5
C.$10.0
C.$12.5
A.$5.0
B.$7.5
C.$10.0
C.$12.5
回答 (1)
2007-04-25 3:22 am
✔ 最佳答案
rice cooker --- 500Wthat mean in 2 hours the rice cookers comsume 1kWh, that is $0.2 dallors.
similarly a 2000W heater consume 1 kWh at half an hour.
Therefore total fee : 0.5 * (10/2) + 0.5 * (10*2) = $12.5
D is the answer
參考: me
收錄日期: 2021-05-03 12:59:17
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070424000051KK03518