An optical filter passes only far red light with an average wavelength of 6500 Å. (1 Å = 10-10 m). Calculate
(a) the wavelength in centimeters.
(b) the frequency.
Convert 6500 A to meters then to cm.
Then c = fw
c is speed of light in m/s
f = frequency in Hz
w = wavelength in m
Post your work if you get stuck.
(a) To convert the wavelength from Ångstroms (Å) to centimeters (cm), we can use the conversion factor 1 Å = 10^-10 m.
Given that 1 cm = 10^-2 m, we can set up a conversion factor:
1 Å = 10^-10 m = x cm
To find x, we multiply both sides of the equation by the conversion factor from meters to centimeters:
1 Å * (1 cm/10^-2 m) = 10^-10 m * (1 cm/10^-2 m)
Simplifying, we find:
x = 10^-10 m * 10^2 cm
x = 10^-10 * 10^2 cm
x = 10^-10+2 cm
x = 10^-8 cm
Therefore, the wavelength in centimeters (cm) is 10^-8 cm.
(b) To calculate the frequency, we can use the formula:
frequency (ν) = speed of light (c) / wavelength (λ)
The speed of light is approximately 3 x 10^8 m/s.
Converting the wavelength from Ångstroms (Å) to meters (m), we use the conversion factor 1 Å = 10^-10 m:
wavelength (λ) = 6500 Å * (10^-10 m/1 Å)
Simplifying, we find:
wavelength (λ) = 6500 * 10^-10 m
Now we can substitute the values into the formula:
frequency (ν) = (3 x 10^8 m/s) / (6500 * 10^-10 m)
First, simplify the denominator:
frequency (ν) = (3 x 10^8 m/s) / (6.5 * 10^-6 m)
To divide by a decimal in the denominator, we multiply the numerator and denominator by a power of 10 to remove the decimal:
frequency (ν) = (3 x 10^8 m/s) * (10^6 / 6.5)
Simplifying, we find:
frequency (ν) = 3 x 10^8 * 10^6 / 6.5
Using the properties of exponents, we add the exponents:
frequency (ν) = 3 x 10^14 / 6.5
frequency (ν) ≈ 4.615 x 10^13 Hz
Therefore, the frequency is approximately 4.615 x 10^13 Hz.
To solve this problem, we can use the relation between wavelength, frequency, and the speed of light. The speed of light is a constant value of approximately 3 x 10^8 meters per second.
(a) To convert the wavelength from angstroms (Å) to centimeters (cm), we can use the conversion factor: 1 Å = 10^-8 cm.
So, the wavelength in centimeters can be calculated as follows:
Wavelength in cm = (Wavelength in Å) x (Conversion factor)
Wavelength in cm = 6500 Å x 10^-8 cm/Å
Wavelength in cm = 6500 x 10^-8 cm
Wavelength in cm = 6.5 x 10^-5 cm
Therefore, the wavelength in centimeters is 6.5 x 10^-5 cm.
(b) To calculate the frequency, we can use the formula:
Frequency = Speed of light / Wavelength
Frequency = (3 x 10^8 m/s) / (Wavelength in meters)
First, let's convert the wavelength in angstroms to meters using the conversion factor: 1 Å = 10^-10 m.
Wavelength in meters = Wavelength in Å x (Conversion factor)
Wavelength in meters = 6500 Å x 10^-10 m/Å
Wavelength in meters = 6500 x 10^-10 m
Wavelength in meters = 6.5 x 10^-7 m
Now we can calculate the frequency:
Frequency = (3 x 10^8 m/s) / (6.5 x 10^-7 m)
Frequency = 4.615 x 10^14 Hz
Therefore, the frequency is approximately 4.615 x 10^14 Hz.