[iMore Question]

I plugged my iPhone 5 to my brother mac to charge and it ask me trust or don't trust and i said trust i think, and now my iPhone 5 is not turning on.

[iHackPro]

Are you using a 3rd party charger?

Read this article : If your iPhone 5 isn't charging anymore, it could be that third party cable you're using | iMore

[Just_Me_D]

I plugged my iPhone 5 to my brother mac to charge and it ask me trust or don't trust and i said trust i think, and now my iPhone 5 is not turning on.

The "Trust this computer" alert happened because you connected your iPhone to a computer it had not been connected to prior. As for your device not charging, it could be the charging cable as stated by Darren Ingram. If the battery was completely depleted, it may needed to be plugged it for a few minutes before you could see that it was charging or to have enough juice to turn on.

[Arktos]

All of the suggestions in this thread are solid, OP. If you don't have any luck with troubleshooting this issue, there is some information here which may be of interest to you:

https://ssl.apple.com/support/iphone5-sleepwakebutton/

The sleep/wake button is a known and addressed issue on some models of the iPhone 5.