Electromagnetic Waves
1. Gamma-ray bursters are objects in the universe that emit pulses of
gamma rays with high energies. The frequency of the most energetic
bursts has been measured at around 3.0 x 10- Hz. What is the wave-
length of these gamma rays?
2. What is the wavelength range for the FM radio band (88 MHz-108 MHz)?
3. Shortwave radio is broadcast between 3.50 and 29.7 MHz. To what range
of wavelengths does this correspond? Why do you suppose this part of
the spectrum is called shortwave radio?
What is the frequency of an electromagnetic wave if it has a wavelength
of 10 km?
5. The portion of the visible spectrum that appears brightest to the human
eve is around 560 nm in wavelength, which corresponds to yellow-green.
What is the frequency of 560 nm light?
6. What is the frequency of highly energetic ultraviolet radiation that has a
wavelength of 125 nm?

After a big snowfall, you take your favorite rocket-powered sled out to a wide field. the field is 195 m across, and you know that your sled accelerates at a rate of 3.65 m/s2 when the rocket is on. how much time will it take the sled to cross the field starting from rest, assuming the rocket is on the whole time?

In positive numbers less than 1, the zeros between the decimal point and non zero are significant

In a thunderstorm, charge builds up on the water droplets or ice crystals in a cloud. thus, the charge can be considered to be distributed uniformly throughout the cloud. for the purposes of this problem, take the cloud to be a sphere of diameter 1.00 kilometer. the point of this problem is to estimate the maximum amount of charge that this cloud can contain, assuming that the charge builds up until the electric field at the surface of the cloud reaches the value at which the surrounding air breaks down. this breakdown means that the air becomes highly ionized, enabling it to conduct the charge from the cloud to the ground or another nearby cloud. the ionized air will then emit light due to the recombination of the electrons and atoms to form excited molecules that radiate light. in addition, the large current will heat up the air, resulting in its rapid expansion. these two phenomena account for the appearance of lightning and the sound of thunder. take the breakdown electric field of air to be eb=3.00ă—106n/c. part a estimate the total charge q on the cloud when the breakdown of the surrounding air is reached. express your answer numerically, to three significant figures, using ďµ0=8.85ă—10â’12c2/(nâ‹…m2) .