Answer:
a) The average force on the kite due to radiation pressure is 2.25 × 10^-6 N.
b) The kite absorbs all the energy, the energy will be converted into heat, leading to an increase in the temperature of the kite. This increase in temperature might lead to other effects such as thermal expansion, change in material properties, etc.
Step-by-step explanation:
(a) To calculate the average force on the kite due to radiation pressure, we can use the formula for radiation pressure:
Pressure= Intensity of Light / c
where:
Intensity of Light (I) = 900 W/m² (given)
c = speed of light in a vacuum = 3.00 x 10^8 m/s (constant)
The area of the kite (A) = 0.75 m² (given)
Now, we can calculate the pressure:
Pressure= 900 W/m2 / 3.00×108 m/s
Pressure=3×10−6 N/m2
Since pressure is force per unit area, the average force on the kite (F) is:
F=Pressure×Area
F=(3×10 −6 N/m2 )×0.75 m2
F=2.25×10 −6 N
So, the average force on the kite due to radiation pressure is 2.25 × 10^-6 N.
(b) If the kite material is black and absorbs all sunlight, the radiation pressure will be the same as in part (a). However, since the kite absorbs all the sunlight falling on it, it will experience a net force in the direction of the incoming light. The radiation pressure will exert a force on the kite, causing it to accelerate in the direction of the sunlight.
The force exerted on the kite due to radiation pressure will be the same as calculated in part (a), i.e., 2.25 × 10^-6 N. However, since the kite absorbs all the energy, the energy will be converted into heat, leading to an increase in the temperature of the kite. This increase in temperature might lead to other effects such as thermal expansion, change in material properties, etc.