## boomerang285 2 years ago Please Help with Practice question!!! An electrically charged particle accelerates uniformly from rest to speed v while traveling a distance x. a) Show the acceleration of the particle is a= v^2/2x. b) If the particle starts from rest and reaches a speed of 1.8 x 10^7 m/s over a distance of 0.10m, show that its acceleration is 1.6 x 10^15 m/s^2.

1. boomerang285

I know for B i just plug in the numbers...

2. shivaniits

you know $v ^{2}-u ^{2}=2as$ and here s=x and u=0 since it started from rest so we have:- $v ^{2}-0=2ax$ $a=v ^{2}/2x$

3. shivaniits

now for second part just put the values for the equation.. hope this helps..!!

4. boomerang285

so the equation for part A is ...

5. boomerang285

v^2-0=2ax?

6. shivaniits

yup that'w what you get after putting in the values x=s and u=0 in more general eqn $v ^{2}-u ^{2}=2as$

7. boomerang285

ok, then for B it comes out like ...

8. boomerang285

[1.8 x 10^7]^2/ {2*0.1) ?

9. shivaniits

yes..

10. shivaniits

hope this sorted you out..!!

11. boomerang285

so it equals ...

12. boomerang285

1.62e + 15 m/s^2 ?

13. boomerang285

thats what comes up on a calculator.....

14. shivaniits

oh..the answer is $16.2 \times 10^{14}$

15. boomerang285

ok.......

16. boomerang285

hmm wonder why mine is so off...

17. shivaniits

everything alright..!!