Wavelength is the distance between identical points in the adjacent cycles of a waveform signal propagated in space or along a wire. In wireless systems, this length is usually specified in meters, centimeters, or millimeters.
Wavelengths are an important factor in Wi-Fi networks. Wi-Fi operates at five frequencies, all in the gigahertz range: 2.4 GHz, 3.6 GHz, 4.9 GHz, 5 GHz and 5.9 GHz. Higher frequencies have shorter wavelengths, and signals with shorter wavelengths have more trouble penetrating obstacles like walls and floors.
As a result, wireless access points that operate at higher frequencies with shorter wavelengths, often consume more power to transmit data at similar speeds and distances achieved by devices that operate at lower frequencies, with longer wavelengths.
Answer:
B. A car of mass 2000 kg with speed 7 m/s
Explanation:
The kinetic energy of an object is given by:
where m is the mass of the object and v is its speed.
From the formula, we see that the larger the mass and the speed of the object, the larger its kinetic energy. Among the choices given, we see that the car with largest mass and largest speed is car B, which has a mass of 2000 kg and speed of 7 m/s. Its kinetic energy is:
We can verify that the other cars have smaller kinetic energy. In fact:
- Car A: 
- Car C: 
- Car D: 
So, car B is the one which has most kinetic energy.
Answer:
Gravitational attraction of the sun.
Explanation:
Gravity is an attractive force. Any two masses will exert an attractive force on the other according to Newton's law of universal gravitation. The more massive the objects, the stronger the force. The sun, as you can probably guess, is pretty massive - 330,000 times more than Earth, and 1,048 time more than Jupiter, our solar system's largest planet. Just like man-made satellites around Earth, the planets in our solar system are constant process of "falling" around the sun, locked in their orbits by its mass, but slowing dramatically in their orbital velocity the further away they are.
Answer:
8 Hz, 48 Hz
Explanation:
The standing waves on a string (or inside a pipe, for instance) have different modes of vibrations, depending on how many segments of the string are vibrating.
The fundamental frequency of a standing wave is the frequency of the fundamental mode of vibration; then, the higher modes of vibration are called harmonics. The frequency of the n-th harmonic is given by
where
is the fundamental frequency
In this problem, we know that the wave's third harmonic has a frequency of
This means this is the frequency for n = 3. Therefore, we can find the fundamental frequency as:
Now we can also find the frequency of the 6-th harmonic using n = 6:
