The cosmic background radiation is A)
the flux of visible radiation in empty space, contributed by all visible stars in the universe.
B)
the radio noise generated by Earth-bound transmitters, spreading out into space since about 1920.
C)
the beam of atomic nuclei known as cosmic rays that continuously rain down upon the Earth from all directions in space.
D)
low-intensity radio noise, with a 3 K blackbody temperature, almost uniform in intensity in all directions.

Consider an ordinary, helium-filled party balloon with a volume of 2.2 ft3. the lifting force on the balloon due to the outside air is the net resultant of the pressure distribution exerted on the exterior surface of the balloon. using this fact, we can derive archimedes’ principle, namely that the upward force on the balloon is equal to the weight of the air displaced by the balloon. assuming that the balloon is at sea level, where the air density is 0.002377 slug/ft3, calculate the maximum weight that can be lifted by the balloon. note: the molecular weight of air is 28.8 and that of helium is 4.

In the first law of thermodynamics, triangle e=q-w, what does q stand for

What’s #16 asking me and how do i solve it?