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

Potential step problem

  • Thread starter tarkin
  • Start date
  • #1
13
0

Homework Statement


Please see attached image. I'm trying to do part (d), then (e) afterwards.

For (d) I can sketch the graph okay, just trying to calculate T now.

Homework Equations


T= 4k1k2/(k1+k2)2

k = ((2m/ћ)2(E-V))½

The Attempt at a Solution



I tried substituting in k into the equation for T. But k depends on the mass of the particle, which isn't given in the question. So what can I do here? I guess one option is just finding the point on the graph, but that's not really a calculation.
 

Attachments

Answers and Replies

  • #2
DrClaude
Mentor
7,337
3,517
I tried substituting in k into the equation for T. But k depends on the mass of the particle, which isn't given in the question. So what can I do here?
Look carefully at the equation for T after having substituted the equation for k.
 
  • #3
13
0
Look carefully at the equation for T after having substituted the equation for k.
When I subbed in k I hoped the m's would cancel but I couldn't get them to. Is it just some mistake I'm making - should they indeed cancel?

Thanks
 
  • #4
DrClaude
Mentor
7,337
3,517
When I subbed in k I hoped the m's would cancel but I couldn't get them to. Is it just some mistake I'm making - should they indeed cancel?
It should. You have k's squared both at the numerator and the denominator.
 
  • #5
13
0
It should. You have k's squared both at the numerator and the denominator.
Okay, I'll take another look at my working out. Thanks a million!
 

Related Threads on Potential step problem

  • Last Post
Replies
0
Views
1K
  • Last Post
Replies
7
Views
2K
  • Last Post
Replies
3
Views
1K
  • Last Post
Replies
0
Views
2K
  • Last Post
Replies
4
Views
3K
  • Last Post
Replies
14
Views
2K
  • Last Post
Replies
4
Views
4K
  • Last Post
Replies
5
Views
3K
  • Last Post
Replies
0
Views
1K
Top