In the 25 ftft Space Simulator facility at NASA's Jet Propulsion Laboratory, a bank of overhead arc lamps can produce light of intensity 2500 W/m^2 at the floor of the facility. (This simulates the intensity of sunlight near the planet Venus.) Required:
Find the average radiation pressure (in pascals and in atmospheres) on

a. A totally absorbing section of the floor.
b. A totally reflecting section of the floor.
c. Find the average momentum density (momentum per unit volume) in the light at the floor.

a) 8.33 x Pa  or  8.22 x atm

b) 1.66 x Pa  or  1.63 x atm

c) 2.77 x kg/m^2-s

Explanation:

Intensity of light = 2500 W/m^2

area = 25 ft^2

a) average radiation pressure on a totally absorbing section of the floor

where I is the intensity of the light

c is the speed of light =

= 8.33 x Pa

1 pa =

8.33 x Pa = 8.22 x atm

b) average radiation for a totally radiating section of the floor

this means that the pressure for a totally radiating section is twice the average pressure of the totally absorbing section

therefore,

Pav = 2 x 8.33 x  = 1.66 x Pa

or

Pav in atm = 2 x 8.22 x = 1.63 x atm

c) average momentum per unit volume is

= 2.77 x kg/m^2-s

answer: the exterior temperature of commercial jet planes as they leave the stratosphere and return to the ground increases steadily.

explanation:

the lower most layer of atmosphere is troposphere which extends from 0 to 12 km above the surface of the earth. the temperature initially decreases as distance is increased from the earth's surface. commercial jets fly in lower part of the stratosphere. the stratosphere extends upto 50 km. the temperature in stratosphere starts rising again due to presence of ozone which traps the uv rays.

thus, when the planes leave the stratosphere and return to the ground, the exterior temperature increases steadily.