小刚为书房买灯,现在有2种灯可共选择,其中一种是9W既(0.009KW)的节能灯,售价49元一盏,另外一种是40W既(0.004KW)的白炽灯售价8元一盏,假设两种灯的照亮度一样,使用寿命都可以达到2800h .已知小刚
来源:学生作业帮助网 编辑:作业帮 时间:2024/08/29 05:05:08
![小刚为书房买灯,现在有2种灯可共选择,其中一种是9W既(0.009KW)的节能灯,售价49元一盏,另外一种是40W既(0.004KW)的白炽灯售价8元一盏,假设两种灯的照亮度一样,使用寿命都可以达到2800h .已知小刚](/uploads/image/z/2081594-2-4.jpg?t=%E5%B0%8F%E5%88%9A%E4%B8%BA%E4%B9%A6%E6%88%BF%E4%B9%B0%E7%81%AF%2C%E7%8E%B0%E5%9C%A8%E6%9C%892%E7%A7%8D%E7%81%AF%E5%8F%AF%E5%85%B1%E9%80%89%E6%8B%A9%2C%E5%85%B6%E4%B8%AD%E4%B8%80%E7%A7%8D%E6%98%AF9W%E6%97%A2%280.009KW%29%E7%9A%84%E8%8A%82%E8%83%BD%E7%81%AF%2C%E5%94%AE%E4%BB%B749%E5%85%83%E4%B8%80%E7%9B%8F%2C%E5%8F%A6%E5%A4%96%E4%B8%80%E7%A7%8D%E6%98%AF40W%E6%97%A2%280.004KW%29%E7%9A%84%E7%99%BD%E7%82%BD%E7%81%AF%E5%94%AE%E4%BB%B78%E5%85%83%E4%B8%80%E7%9B%8F%2C%E5%81%87%E8%AE%BE%E4%B8%A4%E7%A7%8D%E7%81%AF%E7%9A%84%E7%85%A7%E4%BA%AE%E5%BA%A6%E4%B8%80%E6%A0%B7%2C%E4%BD%BF%E7%94%A8%E5%AF%BF%E5%91%BD%E9%83%BD%E5%8F%AF%E4%BB%A5%E8%BE%BE%E5%88%B02800h+.%E5%B7%B2%E7%9F%A5%E5%B0%8F%E5%88%9A)
xURA~6 -\+CrG1
hDQ*HYb$,zҳhyMy{649uHLi-U0Ru(Ti!7*I
H $ZhS5J\WWFnLlQB@bQO.CD`L7cF[MO|cQSFZl D*8o:&K_)/?/y͡__q4iD4$QYbvsc^EOS4ۼ6P-i]0vp%!t/qzx+j:hE:6&ὋTau =v[=sv أ
3G
6lx/GB(~G[QMynOrMuq1x* @.ѓ0nes?
inL@67l,@Ԓ
=!Q$zqPtԳ;AxCɞPrcR̈8ッּ3^`*|lm
$1[*=isYvT1n852KЫcz"d9E[qN5k
sjeq1)+r8XMx4<f%n_