H Value

[Lillie Yazdi 3J]

I'm looking through the textbook answers for certain problems in 1B and a lot of them in the uncertainty equation use the value 1.054x10^-34 for h instead of 6.626x10^34. I'm confused on what value I should use for h??

[Edwin Montalvo 1G]

This might be a discrepancy in the units. 6.626 x 10^-34 for h is in the units of Joules * second, or rather kg⋅m^2⋅s^−1. This means that if you are doing calculations regarding velocity or mass, your units would need to be in m/s or kg in order for it cancel, such as in the Debroglie equation. I would continue to use 6.6.26 x 10 ^ -34 since that is what we've been doing in class, but just remember to make sure the units are consistent. Hope this helps!

[Lauren Brotman 2F]

1.054x10^-34 is h/2pi. You should usually just use the regular h value. This new value could be used as a shortcut for the Heisenberg indeterminacy equation.

[Elena Chan 2L]

Hi! They used 1.054x10^-34 J/s because it the indeterminacy equation can either be planck's constant (6.626 x 10^-34 J/s) divided by 4(pi) or it can be h-bar (ħ) divided by 2(pi) which is 1.054x10^-34 J/s. It depends on what constants you want to use to represent the equation. They can be interchangeable. Hope this helps!

[Mya_Chiarappa_2C]

We should be using the h listed on the equation sheet if we are also using the equation on the equation sheet. The book does it differently because they use a different denominator as well.

[Ishant Goel 2D]

Yes, as Mya said, the best thing to do is just use the values given on the constant and equations sheet for the exam.

[Furkan Acar 3C]

That's probably just h divided by 2pi. I would just use normal values of constants when plugging your constants into equations. Make sure to convert!

[Wilson Zheng 1L]

I believe the normal value of the "Planck's Constant" should be fine; maybe they changed the units into something else to fit the scope of the question (but that's usually unlikely to occur)!

[Omeed Kalan]

Use the value given to us by Professor Lavelle on the equation sheet.

[Sofi Ghasemzadeh 2G]

The h value in Js is 6.626 x 10^34, which is what we have been using in and outside of class. The other value is most likely in other units. Just make sure the units are consistent and you should be good.

[Junyong Wu]

h equal 6.626*10^(-34) J/s