1) What is the radiation pressure exerted on surface which is 1.5 m from a 500 Watt light bulb? Assume that the surface is directly facing the light.

[5.9^.10^-8 N/m²]

2) A laser beam whose power is 4.6 watts (pretty kicky) has a diameter of 2.6 mm. It is directed towards the bottom of a perfectly reflecting cylinder whose density is 1.2 g/cc and whose diameter is less than 2.6 mm. If this cylinder is made to hover in the air in the laboratory what is the height of the cylinder?

[4.8^.10^-7m]

3) An astronaut is stranded in space due to malfunctioning manuvering jets. Fortunately she has along her 10 W Everready flashlight. Given that her mass (with space suit) is 100 kg and that the battery will last for 2.5 hrs how long will it take her to cover the 150 m to the space shuttle by this means?

[5.5^.10⁷ s ]

4) A dust particle floating in space is subject to both gravitational attraction from the sun and radiation pressure pushing it away. The density of such dust particles in our solar system is 1000 kg/cubic meter. What is the diameter of the smallest dust particle you would expect to find in our solar system? (is it dependent on the distance from the sun?) Remember that the intensity of sunlight at the top of the earth's atmosphere is 1400 W/m².

[1.2^.10^-6m]

5) While calibrating a laser the technician places a polarizer in the beam whose transmission axis is oriented vertically. She observes that the intensity of the light is reduced by half. What are the possible orientations of the plane of polarization of the laser light?

[unpolarized or at 45 degrees]

6) Unpolarized light passes through 3 polarizers. The first has a transmission axis which is oriented horizontally. Each succeeding polarizer is rotated 30 degrees with respect to the preceding one. What is the intensity and polarization of the light which exits the third polarizer?

[28% polarized 30 degree to vertical]

7) We want the plane of polarization of the light exiting from our equipment to be horizontal. The light entering our equipment will be polarized vertically. What is the minimum number of polarizers needed inside the equipment to accomplish this? What is the minimum number of sheets required if the intensity of the transmitted light is more than 60% of the incoming light?

[5 filters at 18 degrees is the minimum needed]

8) A beam of partially polarized light consists of a mixture of polarized light and unpolarized light. Suppose you view such light through a single polarizer which you rotate through 360 degrees while recording the intensity of the trasnmitted light. You observe that at its brightest the transmitted light is 5 times as bright as at its dimmest. What percentage of the beam is polarized light?