Wednesday
August 27, 2014

Homework Help: Physics - urgent

Posted by Linn on Tuesday, April 21, 2009 at 9:38pm.

I already asked this and was given an answer, but I don't fully understand it and so would like a further explanation.

What I asked was...

An electron is accelerated through a uniform electric field of magnitude 2.5x10^2 N/C with an initial speed of 1.2x10^6 m/s parallel to the electric field.

a) Calculate the work done on the electron by the field when the electron has travelled 2.5 cm in the field.
b) Calculate the speed of the electron after it has travelled 2.5 cm in the field.
c) If the direction of the electric field is reversed, how far will the electron move into the field before coming to rest?

drwls kindly gave me these answer...
a) e E x
b) Assume the work done (above) equals the increase in kinetic energy
c) It will travel until
E e x = intial kinetic energy

I don't quite understand what drwls means by 'x' in the equation eEx. I got an answer for a using W=qEr and got 1x10^.18 J. According to my book, that's correct. For B I got 1.5x10^6m/s, but my book says that the correct answer should be 1.9x10^6 m/s. Additionally, for C, am I using the same kinetic energy as I did in question b? Would I not just get the same answer as b? I'm just really confused and would appreciate further guidance on this problem.

Answer this Question

First Name:
School Subject:
Answer:

Related Questions

english - I did a exercise with indirect speech, can anybody check it? 1. "Have ...
Calculus - Someone already asked this question but did not understand the answer...
physics - Hi i'm doing that lab were you attach a weight to a tape which is also...
math - ok so I asked a question like this before and I understood how to do it ...
math - what percentile score is equivalent to the lower quartile? but here i ...
math - How many two digit numbers are there in base 5. I really don't understand...
English - Can you please see if everything is correct? Thank you. 1) She said ...
English - Thank you very much! Just one more thing. Should I evaluate the ...
PLEASE VIEW- URGENT! - I do not understand this question. Could you please ...
physics - Suppose you are asked to find the area of a rectangle that is 2.1- ...

Search
Members