Take the 2-minute tour ×
Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free, no registration required.

An electron in a cathode-ray tube is traveling horizontally at 2.10×10^9 cm/s when deflection plates give it an upward acceleration of 5.30×10^17 cm/s^2 .

B.) What is its vertical displacement during this time?

My work http://i.imgur.com/AqKlTuX.jpg

I am asking this because the answer my teacher gave is 2.3cm

Thanks in advance

share|improve this question

closed as too localized by Qmechanic Feb 12 '13 at 0:17

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.

    
For starters, y = y_0 + ut + 0.5at^2, where as you have omitted this 0.5 –  Mew Feb 7 '13 at 5:24
    
And secondly you performed a calculator error as well. See my answer below. –  Mew Feb 7 '13 at 5:28

1 Answer 1

up vote 0 down vote accepted

$y = y_0 + ut + 0.5at^2$

Since $y_0$ and $u$ are $0$, we have $y = 0.5~at^2$.

In your calculation $t = 2.95 \times 10^{-9}$, which is correct.

So, $y = 0.5\times5.30×10^{17}\times (2.95 \times 10^{-9})^2$

Therefore, $y = 2.3~\text{cm}$

share|improve this answer
1  
Thanks Chris. Silly mistake, need to be more careful –  user1530249 Feb 7 '13 at 5:29
1  
No problem user1530249! –  Mew Feb 7 '13 at 5:31

Not the answer you're looking for? Browse other questions tagged or ask your own question.