1B.27 Hw Help


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Bita Ghanei 1F
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Joined: Thu Feb 28, 2019 12:15 am

1B.27 Hw Help

Postby Bita Ghanei 1F » Tue Oct 15, 2019 3:44 pm

A bowling ball of mass 8.00 kg is rolled down a bowling alley lane at . What is the minimum uncertainty in its position?

How do you solve for the change in velocity here? It seems as though we are not given enough information.

Paul Hage 2G
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Joined: Thu Jul 25, 2019 12:17 am

Re: 1B.27 Hw Help

Postby Paul Hage 2G » Tue Oct 15, 2019 4:10 pm

You would use the Heisenberg Uncertainty Equation: ΔpΔx≥h/4pi. This equation is equivalent to mΔvΔx≥h/4pi. So you would now isolate Δv and sub in the values we know. We know, from the problem, that the uncertainty in position, Δx, is 5.0m. The mass is 8.00kg. h is Planck's constant, 6.626 x 10^-34 J s. Using this information, we can isolate Δv and solve.

Sion Hwang 4D
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Joined: Wed Sep 18, 2019 12:21 am

Re: 1B.27 Hw Help

Postby Sion Hwang 4D » Tue Oct 15, 2019 5:24 pm

You use the Heisenberg's Uncertainty Equation.

It states:
ΔmΔvΔx ≥ h/4pi.
You know that the mass is 8.00 kg, h= 6.626 x 10^-34 kg*m^2*s^-1, and Δv is 10m/s. You must isolate Δx.

Hence,

Δx ≥ (6.626 x 10^-34 kg*m^2*s^-1 / 4pi) / (8kg * 10m/s), and you are left with:
Δx ≥ 6.6 x 10^-37 m.

RRahimtoola1I
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Re: 1B.27 Hw Help

Postby RRahimtoola1I » Wed Oct 16, 2019 2:35 pm

For ∆x, I got 6.6 x 10-36m also, but the answer in the back of the book and the solution manual is 1.3 x 10-36m. Which is the correct answer?

AlyssaYeh_1B
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Joined: Sat Aug 17, 2019 12:16 am

Re: 1B.27 Hw Help

Postby AlyssaYeh_1B » Thu Oct 17, 2019 5:19 pm

RRahimtoola1G wrote:For ∆x, I got 6.6 x 10-36m also, but the answer in the back of the book and the solution manual is 1.3 x 10-36m. Which is the correct answer?


The correct answer would be 6.6 x 10-37m. There was an error in the solutions manual (Δv = 5m/s when Δv should've been 10m/s)

805307623
Posts: 99
Joined: Fri Aug 09, 2019 12:17 am

Re: 1B.27 Hw Help

Postby 805307623 » Fri Oct 18, 2019 3:55 pm

If you plug in all the variables the equation: delta x= (1/2)(h/(m*delta v)) should provide the answer straight away.


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