• Support PF! Buy your school textbooks, materials and every day products Here!

Uncertainties in the momentum and kinetic energy of the proton?

  • Thread starter Physics321
  • Start date
  • #1
12
0
1. Homework Statement
A proton in a tin nucleus is known to lie within a sphere whose diameter is about 2.2 multiplied by 10E-14 m. What are the uncertainties in the momentum and kinetic energy of the proton?

2. Homework Equations
delta(x)*delta(p) >= hbar
delta(E)*delta(t) >= hbar


3. The Attempt at a Solution

I understand the first part finding the uncertainty of the momentum, which is simply. . .

1.05E-34 J(s) / (2.2E-14 m) = 4.77E-21 kg(m/s)

I don't however, in any way understand finding the uncertainty in the kinetic energy. . . Howe are we suppose to know this if we aren't told the time (or does that matter). I know the answer should be something times E-14, but I would like to know how to modify and manipulate this equation (delta(E)*delta(t) >= hbar.

Any help would be appreciated.
 

Answers and Replies

  • #2
Redbelly98
Staff Emeritus
Science Advisor
Homework Helper
12,038
128
I think you just need to find the kinetic energy corresponding to the momentum you have calculated.
 

Related Threads for: Uncertainties in the momentum and kinetic energy of the proton?

Replies
2
Views
3K
Replies
1
Views
1K
Replies
1
Views
4K
Replies
3
Views
979
  • Last Post
Replies
1
Views
21K
  • Last Post
Replies
5
Views
368
  • Last Post
Replies
12
Views
24K
Top