Satellite TV is broadcast from satellites that orbit 37,000 kmkm above the earth's surface. Their antennas broadcast a 15 kWkW microwave signal that covers most of North America, an area of about 2.5×107km22.5×107km2.   What is the total power that strikes a 90-cmcm-diameter ground-based dish antenna?   The dish antenna focuses the incoming wave to a 1.0 cm2cm2 area. What is the amplitude of the electric field at this focus?

You and your friend Bruce are experimenting with a red lamp shade and blue lamp shade. You place lamp shades individually over a 120-W light bulb. Assume that the light radiates from the lamps uniformly and 9.5% of their power is converted to light. (a) What is the average intensity of the light at 1.6 m from the red (1 = 710 nm) lamp shade? W/m2 (b) Is the average intensity of the blue (1 = 480 nm) lamp shade at 1.8 m greater than, less than, or equal to the intensity calculated in part (a)? greater than less than O equal to

Assume the mostly infrared radiation from a heat lamp acts like a continuous wave with wavelength 1.50 µm. (a) If the lamp's 205 W output is focused on a person's shoulder, over a circular area 24.0 cm in diameter, what is the intensity in W/m2? 2266.9 W/m2 (b) What is the peak electric field strength in kV/m? 0.924 X kV/m (c) Find the peak magnetic field strength in µT. 3.08 X µT (d) How long will it take in seconds to increase the temperature of the 3.80 kg shoulder by 2.00°C, assuming no other heat transfer and given specific heat is 3.47 x 103 J/(k • °C)? 128.64

A low-cost way of sending spacecraft to other planets would be to use the radiation-pressure on a solar sail. The intensity of the sun's electromagnetic radiation at distances near the earth's orbit is about 1,320 W/m². What size sail (in km²) would be needed to accelerate a 6,906 kg space craft toward Mars at 0.024 m/s²? Assume that the solar sail is perfectly reflecting. (Use c = 2.9979 × 108 m/s) km²

A laser emits a narrow beam of light. The radius of the beam is 3.2 mm, and the power is 1.8 mW. What is the intensity of the laser beam?

AM stations have kHz frequencies. What is the wavelength of local AM station with an assigned frequency 98.2 kHz?

Problem 1:   In order to optimize power, most broadcast antenna have a length that is 1/4 of the wavelength of the electromagnetic waves being transmitted.    If a broadcast antenna is 9 m long, what is the frequency of its transmitted waves?  f =    Hz

The wavelength of a light in air is 559 nm. What is its frequency?

6.a. A light wave has a wavelength of 1,310 nm. What's the frequency of this wave?A. 229 THzB. 914 THzC. 371 THzD. 436 THz 6.b. A light wave has a frequency of 358 THz. What's the wavelength of this wave?A. 917 nmB. 556 nmC. 838 nmD. 1,018 nm

Satellite TV is broadcast from satellites that orbit 37,000 km above the earth’s surface. Their antennas broadcast a 15 kW microwave signal that covers most of North America, an area of about 2.5 x 107 km2.a. What is the total power that strikes a 46-cm-diameter ground-based dish antenna?b. The dish antenna focuses the incoming wave to a 1.0 cm2 area. What is the amplitude of the electric field at this focus?