Electric Field and Kinematic Equations for Acceleration and Time Calculations

[khuliso]

Homework Statement

Homework Equations

F=qe, a= qe/ma, x= vit + 1/2t^2

The Attempt at a Solution

(a) i used the formula a= qe/ma to calculate the acceleration and then substituted in this kinematic equation x= vit + 1/2t^2 then i solved for t taking the initial velocity as zero.
(b) i used the same thinking but using the kinematic equation vf= vi + at

so i wanted to know if i have done the problem correctly , if i am wrong please give me a clue on how to approach this kind of problems

 

[khuliso]

Homework Statement

-e = -1.9x10^-19 c , me= 9.1x10^-31 kg

Homework Equations

F=qe, a= qe/ma, x= vit + 1/2t^2

The Attempt at a Solution

(a) i used the formula a= qe/ma to calculate the acceleration and then substituted in this kinematic equation x= vit + 1/2t^2 then i solved for t taking the initial velocity as zero.
(b) i used the same thinking but using the kinematic equation vf= vi + at

so i wanted to know if i have done the problem correctly , if i am wrong please give me a clue on how to approach this kind of problems

 

[kuruman]

We cannot tell you if you have done the problem correctly if you don't tell us what answer you got.

 

[khuliso]

number (a) my answer is 2.38 x 10^6 s
(b) my answer is -1.25 x 10^21 m/s

 

[kuruman]

number (a) my answer is 2.38 x 10^6 s
(b) my answer is -1.25 x 10^21 m/s

(a) This is about 280 days. Without doing the calculation, I think this is unreasonable.
(b) The speed is 11 orders of magnitude higher than the speed of light. I think this is also unreasonable.

Please show the details of your calculation and how you got these numbers. Then someone should be able to point out where you went wrong. It's also possible that when you write it out for posting, you will pinpoint where you went wrong by yourself. It happens sometimes.

 

[Orodruin]

How are we going to know if you did it correctly if you do not show us exactly what you did and tell us what results you got?

x= vit + 1/2t^2

This is incorrect. I would suspect a typo, but you have written it in the same way twice. Make sure you get the relation correctly.