HW 1a 7b


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Lung Sheng Liang 3J
Posts: 85
Joined: Wed Sep 30, 2020 9:33 pm

HW 1a 7b

Postby Lung Sheng Liang 3J » Sat Oct 17, 2020 6:02 pm

When an electron beam strikes a block of copper, x rays with a frequency of 2.0 x 10^18 Hz are emitted. What is the frequency of the wavelengths in picometers?

Does light striking the block of copper affect the calculations at all? Or is it just a simple into plug and chug into c= λv? Also, I got 150pm, is this right?

Sreeram Kurada 3H
Posts: 88
Joined: Wed Sep 30, 2020 10:00 pm

Re: HW 1a 7b

Postby Sreeram Kurada 3H » Sat Oct 17, 2020 6:22 pm

Yes the answer is 150pm. You could check your answers on sapling btw. It's in the homepage of sapling titled Atkins_7e_SSM. Yeah, I would basically plug and chug into that equation.

Nathan Tong 3G
Posts: 86
Joined: Wed Sep 30, 2020 9:49 pm

Re: HW 1a 7b

Postby Nathan Tong 3G » Sat Oct 17, 2020 6:54 pm

Yes, you are correct. All you need to do to solve the problem is plug in c = 3 x 108 and v = 2.0 x 1018 into λ = c/v, and then convert to picometers by multiplying by 1012.

Dylan_Nguyen_2C
Posts: 82
Joined: Wed Sep 30, 2020 9:41 pm

Re: HW 1a 7b

Postby Dylan_Nguyen_2C » Sun Oct 18, 2020 4:56 pm

For this one, I first plugged in the values for c = λv equation
2.99x10^8 = λ(2.0x10^18)
λ = (2.99x10^8)/(2.0x10^18)
λ = 1.495x10^-10
Then I multiplied the result by 1x10^12 to convert to picketers
(1.495x10^-10)(1x10^12) = 149.5 pm
You are correct; the answer is around 150 pm

rhettfarmer-3H
Posts: 96
Joined: Wed Sep 30, 2020 9:59 pm

Re: HW 1a 7b

Postby rhettfarmer-3H » Sun Oct 18, 2020 5:57 pm

This problem is simple rearrangement of the equation c=wavelength times frequency. Thus, to relate frequency to wavelength we get wavelength=c/v. so now we just plug in the wave length we got and then we get it in meters. From here we must convert m to picom. Which is 1m is 10^12 pico meters. so multiply by 10^12. AS SHOWN IN WORK.
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