Which two statements are true of electromagnetic waves?

A guitar string with a length of 80.0 cm is plucked. The speed of a wave in the string is 400 m/sec. Calculate the frequency of

Sholpan [36]

Answer:

The first harmonic is: 250Hz, second harmonic 500Hz, third harmonic 750Hz.

Explanation:

Use the frequency f, speed v, and wavelentgh L relationship:

$v = f\cdot L\implies f = \frac{v}{L}$

We are given the speed v=400 m/s. The base wavelength on a string of length 80cm is twice the length of the string (a "half wave" along the full length of the string), so:

$f = \frac{400\frac{m}{s}}{2\cdot0.8 m}= 250\frac{1}{s}=250 Hz$

The fundamental frequency (first harmonic) is 250 Hz

The second harmonic is produced by one full wave across the string (adding one node in the middle), so L=80cm in this case, therefore the second harmonic frequency is: f2 = 2*250=500Hz

the third harmonic add another node (and a half wave) to the pattern and the wavelength will be 2/3 of 80cm, so f3=3*250Hz = 750Hz

8 0

3 years ago

The ability to attract electrons is known as:

german

The ability to attract electrons is called electronegativity.

8 0

3 years ago

An electric hair dryer is rated 350w 110v. the safety fuse in the circuit can withstand 12a of current. how many hair dryers can

spayn [35]

To determine the number of hair dryers that can be plugged in to a circuit, our basis is the maximum threshold of the current. The current which measures 12 Amperes. This current already incorporates the safety factor that is important in industrial setting.

The voltage and the current can be related to the power by the equation:

P = I*V, where I is the current in Amperes and V is the voltage in volts

Solving for the total power:

P = 12 A * 110 V
P = 1,320 Watts

Since the power rating of each hair dryer is 350 W, we divide this to the total power to determine the capacity.

Number of hair dryers = 1,320 Watts/350 Watts per hair dryer
Number of hair dryers = 3.77

In this case, we cannot round off to 4 because this would already exceed the maximum power capacity. Therefore, the total number of hair dryers allowable is 3.

8 0

4 years ago

arrange the following sound waves according to speed from the slowest to the fastest: The sound waves in steel,The sound waves i

Paladinen [302]

The basic concept that needs to be understood is that sound travels faster through a dense medium. Now if we check the options given in the question, then they should be arranged in the manner given below.
1. The sound waves in hot air.
2. The sound waves in cold air.
3. The sound waves in water.
4. The sound waves in steel.

8 0

3 years ago

The wavelength of light visible to the human eye is on the order of 5 x 10-7 m. if the speed of light in air is 3 x 108 m/s, fin

juin [17]

The frequency of light wave is 0.6*10^15 Hz.

The relation between the speed of light, frequency, and wavelength is given as

c=λν

Plugging the values in the above equation

3*10^8=5*10^(-7)*ν

ν=0.6*10^15 Hz.

Therefore the frequency of the light wave is 0.6*10^15 Hz.

6 0

4 years ago