## anonymous 4 years ago An OpenStudy user's speed is 40 medals per day and his acceleration is 2 medal/day^2. If it takes 4,500 medals to reach the Legend rank, how many days will it take for him to reach the rank?

1. anonymous

lol in first

2. anonymous

wrong group

3. anonymous

isnt it math?

4. anonymous

What is his/her initial medalage? does he/she start from 0?

5. anonymous

physics

6. anonymous

yup 0

7. anonymous

but isnt this an ordinary math problem too?

8. anonymous

i mean the basic concepts still come in play

9. anonymous

its both, physics and math.Arguably physics is nothing without math though :)

10. anonymous

lol can we just teach me how to solve this? :p

11. anonymous

well first of all, his acceleration cant be 2 medals/day a = v / t since you postulated that v = 40 per day a = 40 per day because a = delta V / delta t

12. anonymous

but my book says 50 days o.O

13. anonymous

I would consider it an initial velocity. Its like saying a car is going at 40 ft/s, and accelerating at 2 ft/s^2.

14. anonymous

yeah that'swhat i think too

15. anonymous

To solve the problem use the formula:$d = x_0+v_0t+\frac{1}{2}at^2$Set d to 4500, intial position to 0, intiial velocity to 40, and acceleration to 2. Solve for t.

16. anonymous

so 4500 = 40t + t^2?

17. anonymous

yep

18. anonymous

hmm yep i think that gives 50thanks