Question

In the 25-ft Space Simulator facility at NASA's Jet Propulsion Laboratory, a bank of overhead arc lamps can produce light of intensity 2500W/m22500W/m2 at the floor of the facility. (This simulates the intensity of sunlight near the planet Venus.)A) Find the average radiation pressure (in pascals) on a totally absorbing section of the floor.
B) Find the average radiation pressure (in atmospheres) on a totally absorbing section of the floor.
C) Find the average radiation pressure (in pascals) on a totally reflecting section of the floor.
D) Find the average radiation pressure (in atmospheres) on a totally reflecting section of the floor.

Answer 1

Answer:

0.00000833 Pa

$8.2210708117\times 10^{-11}\ atm$

0.0000166 Pa

$1.6382926227\times 10^{-10}\ atm$

Explanation:

I = Light intensity = 2500 W/m²

c = Speed of light = $3\times 10^8\ m/s$

Pressure is given by

$P=\dfrac{I}{c}\\\Rightarrow P=\dfrac{2500}{3\times 10^8}\\\Rightarrow P=0.00000833\ Pa$

The pressure is 0.00000833 Pa

In atm

$\dfrac{0.00000833}{101325}=8.2210708117\times 10^{-11}\ atm$

The pressure is $8.2210708117\times 10^{-11}\ atm$

For total reflection

$P=\dfrac{2I}{c}\\\Rightarrow P=\dfrac{2\times 2500}{3\times 10^8}\\\Rightarrow P=0.0000167\ Pa$

The pressure is 0.0000166 Pa

In atm

$\dfrac{0.0000166}{101325}=1.6382926227\times 10^{-10}\ atm$

The pressure is $1.6382926227\times 10^{-10}\ atm$