Practice 1. Nitrogen and oxygen
en and oxygen in their liquid states have densities only 0.8 and 0.9
water. Atmospheric pressure is due primarily to the weight of nitro-
and oxygen gas in the air. If the atmosphere liquefied, would its depth
be greater or less than 10.3 m?

In both cases the height is greater than 10.3 m

Explanation:

Pressure is defined by the relationship

       P = F / A

in this case the force is the weight of the two gases

       F = W = m g

If we use the definition of density

      ρ = m / V

      V = A h

      m = ρ A h

we substitute

       P = ρ g h

       h =

For this case the density of the gases is

       ρ' = 0.9

       h =

we calculate

     ρ’= 0.9 \rho_{water}

     h = 1 105 / (0.9 1000 9.8)

     h = 11.3 m

      ρ’= 0.8 \rho_{water}

       h = 1 105 / (0.8 1000 9.8

       h = 12.8 m

In both cases the height is greater than 10.3 m

6 cos 34, 6 sin 34 trig

5 w for 1hr = 5x60x60 joules=300x60=3000x6=18,000j as total energy conversion. efficiency of bulb needed for radiant to thermal within 18000