Achieve Homework Question #13

[MiaRosati3L]

Question 13 asks: The E.coli bacterium is about 2.0 μm long. Suppose you want to study it using photons of that wavelength or electrons having that de Broglie wavelength. What is the energy E photon of the photon?

I got the right answer for the first part of the question, which asks for the energy of the photon. I did E = hc / lambda = (6.626x10^-34)(3.00x10^8) / 2x10^-6 = 9.939x10^-32. The correct answer is actually 9.939x10^-20. How did I mess up the exponent? Did I convert micrometers to meters incorrectly for the wavelength?

I feel like when solving problems for the homework I often get the right numbers but the wrong value for the exponent, and I don't want to make those sorts of mistakes on the midterm.

[William Huang 1K]

You accidentally used 2*10^6 instead of 2*10^-6. Hope this helps!

[Cindy Vo 3E]

You are correct that micro means 10^-6, but I think when inputting the numbers into your calculator you put 2x10^6 instead of 2x10-6. I'm the same with getting the numbers right, but different exponents. Typically, I like to double-check my work before moving on. But luckily, since the exam is multiple-choice, it shouldn't be too stressful with the exponents. Just make sure you know the common conversions, such as kilo, mili, nano, and micro.

[MiaRosati3L]

You accidentally used 2*10^6 instead of 2*10^-6. Hope this helps!

That's hilarious omg, thank you for catching that!

[MiaRosati3L]

You are correct that micro means 10^-6, but I think when inputting the numbers into your calculator you put 2x10^6 instead of 2x10-6. I'm the same with getting the numbers right, but different exponents. Typically, I like to double-check my work before moving on. But luckily, since the exam is multiple-choice, it shouldn't be too stressful with the exponents. Just make sure you know the common conversions, such as kilo, mili, nano, and micro.

Thank youuuu <3