Problem for the extra credit: a telescope consists of a single pos- itive lens of diameter 1 m and focal length 20 m and a ccd camera with 2048 × 2048 square pixels with 9 μm big pixels, placed in the focus of the lens. tele- scope is observing a binary star with two components, separated by 3 × 108 km, 5 light-years away. what is the angular resolution of this telescope? can the telescope see these two stars separated? (i. e. can it 'resolve them)? if yes, what is the distance between the stars on the ccd image (in pixels)? how big are the images of the stars on the ccd (in pixels)? what is the 'field of view of the camera?

Explain in physical terms how a microwave oven works. what would happen when you put a conductor in the microwave oven? explain.

Chapter 23, problem 075 the figure shows a geiger counter, a device used to detect ionizing radiation (radiation that causes ionization of atoms). the counter consists of a thin, positively charged central wire surrounded by a concentric, circular, conducting cylindrical shell with an equal negative charge. thus, a strong radial electric field is set up inside the shell. the shell contains a low-pressure inert gas. a particle of radiation entering the device through the shell wall ionizes a few of the gas atoms. the resulting free electrons (e) are drawn to the positive wire. however, the electric field is so intense that, between collisions with gas atoms, the free electrons gain energy sufficient to ionize these atoms also. more free electrons are thereby created, and the process is repeated until the electrons reach the wire. the resulting "avalanche" of electrons is collected by the wire, generating a signal that is used to record the passage of the original particle of radiation. suppose the radius of the central wire is 24 âµm, the inner radius of the shell 2.3 cm, and the length of the shell 14 cm. if the electric field at the shell's inner wall is 2.8 ă— 104 n/c, what is the total positive charge on the central wire?

Aheavy piece of hanging sculpture is suspended by a90-cm-long, 5.0 g steel wire. when the wind blows hard, the wire hums at its fundamental frequency of 80hz. what is the mass of the sculpture?