## AravindG 4 years ago doubts on gravitation,mechanical properties etc

1. AravindG

HI THX FOR CMING ...i hav many doubts so pls stay k?

2. TuringTest

Sure, I'll try

3. AravindG

wow thx

4. AravindG

xplain tangential acceleration and radial acceleration .how to find net acceleration?when are the cases when they become 0 alternatively?

5. AravindG

turing?

6. TuringTest

|dw:1329408300806:dw|the terms are not quite what I'm used to, but radial acceleration is a result of the change in direction of the object:$a=\frac{v^2}r$it is because the motion vector changes that we get this acceleration (change in direction always means acceleration is happening) so if the object is moving in a straight line the radial acceleration (I call it centripetal acceleration) is zero

7. TuringTest

this illustrate that the change in direction causes an acceleration because the velocity vector changes|dw:1329408593274:dw|As for tangential acceleration that is a result of the object speeding up or slowing down linearly. if, say, we have an object moving in a circular path we have$a=\alpha r$where alpha is the angular acceleration:$\alpha=\frac{d\omega}{dt}$So if the angular velocity is changing, the object is experiencing a tangential acceleration.

8. AravindG

k

9. AravindG

so radiall acc does not contribute to change in angular velocity?

10. AravindG

doubt 2:when an apple falls towards earth the earth moves up to meet the apple .is this true xplain?

11. TuringTest

no radial acceleration happens just by virtue of the object turning, tangential means the object is actually speeding up along the direction of motion (circle, line, whatever) Last question: Yes this is true, because the all forces come in action-reaction pairs. Because the earth exerts a force (gravity) on the apple, the apple exerts a gravity force on the earth. The magnitudes of those forces are the same, therefor the earth doesn't move much, but it must theoretically move some.

12. AravindG

hey why does earth move less?

13. TuringTest

because it is more massive, and$F=ma$m of the apple is small, and m of the earth is large, so the same force on the apple and earth will cause a much greater acceleration on the smaller mass (the apple) than the earth

14. AravindG

k so a body in uniform circular motion has 0 tangential acceleration?

15. TuringTest

right

16. AravindG

do u know applications of modulus of elasticity?

17. TuringTest

if v1=v2 from one point to the next we have 0 change in tangential velocity, which is tangential acceleration of 0|dw:1329409969038:dw|

18. TuringTest

mmm... I never really studied that stuff much. which modulus are we talking about, young's?

19. AravindG

ya

20. AravindG

turing?

21. AravindG

|dw:1327595834758:dw|

22. AravindG

beam of girder is I shape why?

23. AravindG

srry or girder

24. TuringTest

hmm... not sure I can answer that effectively

25. AravindG

what does product of speed and area give us?

26. TuringTest

not sure I understand what you mean

27. TuringTest

area of what?

28. AravindG

area of crossection of a tube

29. AravindG

and speed of water thriugh it

30. ash2326

Volume of water /second

31. TuringTest

well area times velocity is a constant for an incompressible fluid like water, so when the tube narrows the speed of the water increases. I'm pretty sure they multiply to unit volume passing though the area in question

32. TuringTest

^oh good, I'm right

33. AravindG

ya hw u got that?

34. ash2326

Speed= distance/ time Area*distance/time Volume/time

35. TuringTest

...or just looking at units$v\times A=\frac ms\cdot m^2=\frac{m^3}{s}$which at least suggests it's volume over time

36. AravindG

k

37. AravindG

hey turing hw long will u be here?

38. AravindG

(Also ash)

39. AravindG

:P

40. ash2326

41. TuringTest

Mexican holiday today, but I still gotta eat breakfast :P

42. AravindG

i dont need rotation help k i hav some other doubts

43. AravindG

hey turing tell time

44. ash2326

I'll be here for 5 minutes more, have to study

45. AravindG

:P

46. AravindG

me 2 thats y i enquired

47. TuringTest

I'll be here until I get hungry!

48. AravindG

u see i get a lot of doubts wen i study

49. AravindG

i want to make sure smone will be here to help me

50. AravindG

u see i hav imp exams

51. ash2326

Aravind preparing for JEE?

52. AravindG

yes

53. AravindG

nic guess

54. ash2326

I will get my brother to help you some time, he knows much more than me

55. AravindG

so turing can i cm online after smtime with a bunch of doubts pls be here :P

56. AravindG

@ash wow where is he studying ??iwhats his name?>

57. TuringTest

yeah, most likely in an hour or two is good

58. ash2326

He's in IIT Bombay, his name is suyash

59. AravindG

k thx pal i wanna be the topper in the xam pray for me and help me k?

60. AravindG

wow is he there in openstudy?

61. ash2326

ok, i'll surely. He's there but comes very less

62. AravindG

k can u tell him ...its my biggest aim to reach iit pls tell him to come ...i would be glad if he is willing to use skype :P

63. AravindG

ash?

64. ash2326

Aravind G, he can't use skype, he doesn't have laptop but I'll ask him to come. And I'll also try to help you out. You can find me more here