Textbook Problem 1B27

[Constance Newell]

1B.27 A bowling ball of mass 8.00 kg is rolled down a bowling alley lane at
5.00±5.0m⋅s−1. What is the minimum uncertainty in its position?

Could someone explain why we don't convert 8.00kg to grams in this problem

Thank you!

[Sabina House 2A]

SI units are always in kg, not g. Because of this, the constant h used in the Heisenberg's indeterminacy equation is in units of J/s, and 1 J = 1 kg m^2 s^-2. Because the constant h uses kg, you must use units of kg for the mass.

[Isaac Wen]

We've been using grams in the previous chapter because molar mass is in g/mol. Now, since we're no longer dealing with molar mass, we use the standard SI unit, kg!

[DanielHong2L]

1B.27 A bowling ball of mass 8.00 kg is rolled down a bowling alley lane at
5.00±5.0m⋅s−1. What is the minimum uncertainty in its position?

Could someone explain why we don't convert 8.00kg to grams in this problem

Thank you!

I'm also confused in the uncertainty in position. I thought Dr. Lavelle explained that if it was +/- 5.0 m/s then the uncertainty would be 5*2; so delta v = 10. However, the txtbook answer simply uses 5 as the delta v to calculate it.

If anyone / mods can clarify this that'll be amazing!

[DanielHong2L]

1B.27 A bowling ball of mass 8.00 kg is rolled down a bowling alley lane at
5.00±5.0m⋅s−1. What is the minimum uncertainty in its position?

Could someone explain why we don't convert 8.00kg to grams in this problem

Thank you!

I'm also confused in the uncertainty in position. I thought Dr. Lavelle explained that if it was +/- 5.0 m/s then the uncertainty would be 5*2; so delta v = 10. However, the txtbook answer simply uses 5 as the delta v to calculate it.

If anyone / mods can clarify this that'll be amazing!

Oh oops nevermind just checked other post on this same problem. They said it's a txtbook error (check on dr lavell's website answer key thing) so

tl;dr:

The uncertainty in poisition is *2 the +/- so it'd be 10 m/s because that includes both the possibility of being +5 and -5.

[905290504]

for uncertainty you want to keep it in kg because planck's constant's units are J*s which is a simplification of (kg*m^2*s^-2)(s)
*** 1 J = kg*m^2*s^-2

[905290504]

for uncertainty you want to keep it in kg because planck's constant's units are J*s which is a simplification of (kg*m^2*s^-2)(s)
*** 1 J = kg*m^2*s^-2