## anonymous 4 years ago Anybody here good at physics and curious to know how long it takes a speeding Moped to reach Ke$ha? • This Question is Closed 1. anonymous The moped accelerates uniformly over a time of 5.21 seconds for a distance of 110 meters. I have to a) find the average velocity, b) find the velocity at 5.21 seconds, and c) determine acceleration of the Moped. 2. anonymous I'm pretty sure that the average velocity is 21.11 m/s (distance/time), but I'm unsure how to solve the others. Help? 3. anonymous does the moped start from rest? 4. anonymous I'm assuming so 5. anonymous My formula chart sez $\Delta d = v_i \Delta t + \frac{1}{2}a (\Delta t)^2$ and you know d, v_initial, and t, so it's easy to solve for "a" ... 6. anonymous average velocity= (u+v)\2=21.21 m\s v=u+at u+v=42.22 m\s 7. anonymous final velocity is pretty fast, can we hope that Ke$ha won't be able to get out of the way of the speeding moped?

8. anonymous

42.22-u=u+at 2u=42.22-5.21 a

9. anonymous

lol @ fixer... but your formula is way too intense for me :) I think that there's a way to figure it out without one other than the basics...

10. anonymous

ravi: what do u and v stand for?

11. anonymous

i think ravi is saying that final velocity is twice average velocity (since initial velocity is zero), and than acceleration is (final velocity) / (time).

12. anonymous

a=(42.22-2u)\2 u=initial velocity v=final velocity a=acceleration

13. anonymous

hold on... let me process that information...

14. anonymous

ravi- how'd you get 21.21? My calculations give 21.11

15. anonymous

sir, it was written by mistake

16. anonymous

okay, so it is 21.11? and then from there you said that velocity=initial velocity + acceleration * time?

17. anonymous

yeah

18. anonymous

and after that was initial velocity + final velocity= 42.22 m/s. Where did 42.22 come from?

19. anonymous

everyone whos good at physics are at physics group

20. anonymous

no one in the physics group :P

21. anonymous

distance traveled=(average velocity). time=110

22. anonymous

im glad some one could help u

23. anonymous

20ppl there

24. anonymous

Ravi? Where's u go :(

25. anonymous

i am here

26. anonymous

u+v=42.22 v-u=5.21 a so adding these equation, we get 2v=42.22+5.21a

27. anonymous

v=(42.22+5.11a)\2

28. anonymous

a=(v-u)\t if moped started from rest then a=v\t=v\5.11

29. anonymous

now we have final equation for v v=( 42.22+5.11*(v\5.11) ) \ 2 solving this equation for v, we can find the value of final velocity .

30. anonymous

here average velocity= (u+v)\2