/sci/ - Science & Math

I'm taking an online physics course and I need help figuring a concept out, my professor gave this example:

"A raft made of balsa wood has an area of 10m by 10m and a thickness of 10cm. It is placed on a fresh water lake. What percentage of the raft will be above the water?
Fb has to support the weight of the raft: Fb=m*g=rho*V*g=120*10*9.8=11760N "

Can you explain where the 120 comes from?

>chemistry lab
>"put on your goggles."
>fog everywhere.

Any tips? It's annoying having to leave the lab to de-fog every five minutes and I seem to radiate thousands of degrees F, so even anti-fog goggles hardly do shit.

Which opens more doors, a BS or a BE?

Same major, mind you, but different schools give different types of degrees. Does it matter at all?

Wouldn't it be optimal for all classes to be recorded and posted online for students to access at any time? The reason people love those Khan Academy vids is because you can pause, rewind, and go over concepts again at your own desire.

This way students could both interact with their teacher in class and go over concepts they might have had trouble understanding outside of class.