The sun exists in a state of equilibrium between the force of gravitation and
A.the outward radiation pressure from fusion reactions
B.the outward force due to nuclear fission
C.the centrifugal force due to its rotation
D.none of the above
A.the outward radiation pressure from fusion reactions
B.the outward force due to nuclear fission
C.the centrifugal force due to its rotation
D.none of the above
A.0?
B.90?
C.45?
D.30?
A.helium and hydrogen
B.oxygen and nitrogen
C.helium and carbon dioxide
D.oxygen and hydrogen
A.the ratio of useful refrigeration to the net work
B.the ratio of net work to the useful refrigeration
C.the drop in temperature achieved
D.the drop in pressure achieved
A.40 litre
B.40 kilolitre
C.25 litre
D.2500 litre
A.5? per hour
B.10? per hour
C.15? per hour
D.30? per hour
A.is one example of a steady-flow expansion
B.can be performed in a pipe with a restriction
C.of a perfect gas is one of constant enthalpy
D.all of the above
A.three valence electrons
B.four valence electrons
C.five valence electrons
D.six valence electrons
A.30?C
B.45?C
C.60?C
D.90?C
A.higher temperature
B.lower temperature
C.same temperature
D.none of the above