A 40-W lightbulb is 2.2 m from a screen. What is the intensity of light incident on the screen? Assume that a lightbulb emits radiation uniformly in all directions (i.e., over 4π steradians).
formula for intensity
I = P/A
since lightbulb emits radiation uniformly in all directions
A= 4 pi r^2
I = P/ 4pi r^2
=40 W/ 4 pi (2.2)^2
=0.657 W/m^2
A 40-W lightbulb is 2.2 m from a screen. What is the intensity of light incident...
A light bulb emits spherical electromagnetic waves uniformly in all directions. Find (a) the intensity, (b) the radiation pressure, and (c) the electric and magnetic field magnitudes at a distance of 3.0 m from the light bulb, assuming that 50 W of electromagnetic radiation is emitted
What is the radiation pressure 1.20 m away from a 400 W lightbulb, in N/m?? Assus that the surface on which the pressure is exerted faces the bulb and is perfectly absorbing and that the bulb radiates uniformly in all directions.
The mean distance between the Earth and the Sun is 1.50×1011 m. The average intensity of solar radiation incident on the upper atmosphere of the Earth is 1390 W/m2. Assuming that the Sun emits radiation uniformly in all directions, determine the total power radiated by the Sun.
The mean distance between the Earth and the Sun is 1.50×1011 m. The average intensity of solar radiation incident on the upper atmosphere of the Earth is 1390 W/m2. Assuming that the Sun emits radiation uniformly in all directions, determine the total power radiated by the Sun Sulamit Answar Incorrect. Tries 1/12 Previous Tries
If a 100-W lightbulb emits 3.5 % of the input energy as visible light (average wavelength 550 nm) uniformly in all directions. A.How many photons per second of visible light will strike the pupil (4.0 mm diameter) of the eye of an observer 1.3 m away? B.How many photons per second of visible light will strike the pupil (4.0 mm diameter) of the eye of an observer 1.3 km away?
If a 80-W lightbulb emits 3.0 % of the input energy as visible light (average wavelength 550 nm) uniformly in all directions. Part A How many photons per second of visible light will strike the pupil (4.0 mm diameter) of the eye of an observer 1.3 m away? Part B How many photons per second of visible light will strike the pupil (4.0 mm diameter) of the eye of an observer 1.5 km away?
If a 120-W lightbulb emits 2.5 % of the input energy as visible
light (average wavelength 550 nm) uniformly in all directions.
Part A
How many photons per second of visible light will strike the
pupil (4.0 mm diameter) of the eye of an observer 1.6 m away?
Express your answer using two significant figures.
Part B
How many photons per second of visible light will strike the
pupil (4.0 mm diameter) of the eye of an observer 1.5 km...
A light source emits EM waves of 4.00 W total power uniformly in all directions. Assume the wave have a single frequency (monochromatic) a) What is the intensity of the waves at 2.00 m from the light source? b) What iw the electric eld amplitude Eo produced at 2.00 m from the light source?
1) What is E0 at a point 2.40m from a light source whose output is 18 W? Assume the bulb emits radiation of a single frequency uniformly in all directions. (include appropriate units) 2) What is B0 at a point 2.40m from the light source? (include appropriate units)
8. A polarized light that has an intensity I0 = 62.0 W/m² is incident on three polarizing disks whose planes are parallel and centered on a common axis. Suppose that the transmission axis of the first polarizer is rotated 14° relative to the axis of polarization of the incident light, and that the transmission axis of each additional analyzer is rotated 14° relative to the transmission axis of the previous one. Calculate the transmitted intensity through all polarizers. _________ W/m2