High CPU usage

[y0da]

HI, I've got Acer Aspire V15 and I have installed Kali2 and sometimes (maybe twice an hour, sometimes five times) my pc freezes for 15 seconds (maybe) and I hear silent strange noise, this is caused by high CPU usage but I have open only Iceweasel or Netbeans. Can someone help me why this hapens?
I have this pc for one month but this freezing came only week or two later.

[pyth0n]

Open a terminal and keep htop open, it will list all running processes, resources and virtual memory.

Have you installed kali for root user only or created a second user account?

[y0da]

I don't use root account I have my own second

[y0da]

Since I started using htop, my laptop didn't freeze yet but sometimes I can hear that strange noise and when I hear it I observe that iceweasel make high cpu usage and sometimes gnome-shell (about 40% of CPU).