Question

An electron with initial velocity v0 = 1.5 ✕ 105m/s enters a region 1.0 cm long where it is electrically accelerated. It emerges with velocity v = 6.60 ✕ 106 m/s. What was its acceleration, assumed constant?

Answer 1

can i use the d=rt to get the time

.01= 6.60*10^6 * t

Answer 2

t=1.5625*10^-9

Answer 3

can you help

Answer 4

you can use a chart like this one

http://www.studyphysics.ca/newnotes/20/unit01_kinematicsdynamics/chp04_acceleration/images/formulas.GIF

to help you figure out what formula to use

Answer 5

i used the equatioon (v^2-v^0)/2x

Answer 6

in this case, we don't need or care about the time t

so look for the row that has an X under the t column (that's row 4)

Answer 7

so yeah, you'll use \[\Large V_f^2 = V_i^2 + 2ad\] and solve for 'a'. It sounds like you are using the right formula

Answer 8

yes and i got

(6.60*10^6)^2 - (1.5*10^5)^2 /2(.01)

Answer 9

my answer still came out wrong

Answer 10

it supposed to be in m/s^2

Answer 11

ok one sec

Answer 12

ok

Answer 13

I'm getting this roughly 2.176875*10^15

is that what you got?

Answer 14

i got 2.1*10^13

Answer 15

oh so if you use 2 sig figs, then I'd round 2.176875*10^15 to 2.2*10^15

Answer 16

and I wouldn't round until all the calculations are done

Answer 17

so did i have the original set up right

Answer 18

yes you have the right equation

Answer 19

and you plugged in the values correctly

Answer 20

thanks

Answer 21

if it still doesn't accept that answer, then perhaps there's a typo or some computer glitch (making the computer really picky, idk)

Answer 22

it right

Answer 23

ok great