Why does a shuttle need to have a tank containing oxygen?

During the experiment if you could triple the breakaway magnetic force with all other quantities left unchanged, what is the new value for the critical velocity if it was v0 (initial velocity), initially? (b) now if you halved the radius with all other quantities left unchanged, what is the new critical velocity if it was v0 (initial velocity), initially? (c) if during the experiment, critical velocity quadrupled with all other quantities left unchanged, what is the new breakaway force if its magnitude was initially f0,?

Matter that emits no light at any wavelength is called

Suppose your surface body temperature averaged 90 degrees f. how much radiant energy in w/m^2 would be emitted from your body?