Answer: Electromagnetic waves are generated by moving electrons. An electron generates an electric field which we can visualize as lines radiating from the electron Figure 10a. If the electron moves, say it vibrates back and forth, then this motion will be transferred to the field lines and they will become wavy Figure 10b.
The correct choice is
D. 22 Hz and 42 Hz.
In fact, the beat frequency is given by the difference between the frequencies of the two waves:
In this problem, the beat frequency is 
, therefore the only pair of frequencies that gives a difference equal to 20 Hz is
D. 22 Hz and 42 Hz.
Answer:(10.69, 11.436)
Explanation:
Given
initial height of ball is 2 m
height of basket is 3.05 m
Launching angle
y=1.05
equation of trajectory of ball is given by
for x=12.27
u=10.69
for x=11.73
u=11.436 m/s
Thus range of speed is (10.69, 11.436)
Answer:
If the radio wave is on an FM station, these are in Megahertz. A megahertz is one ... Typical radio wave frequencies are about 88~108 MHz .
Explanation:
To calculate the wavelength of a radio wave, you will be using the equation: Speed of a wave = wavelength X frequency.
Since radio waves are electromagnetic waves and travel at 2.997 X
10
8
meters/second, then you will need to know the frequency of the radio wave.
If the radio wave is on an FM station, these are in Megahertz. A megahertz is one million hertz. If the radio wave is from an AM radio station, these are in kilohertz (there are one thousand hertz in a kilohertz). Hertz are waves/second. Hertz is usually the label for the frequency of electromagnetic waves.
To conclude, to determine the wavelength of a radio wave, you take the speed and divide it by the frequency.
Typical radio wave frequencies are about
88
~
108
MHz
. The wavelength is thus typically about
3.41
×
10
9
~
2.78
×
10
9
nm
.
