ابغى الحلول ضروري اليوم بلييييز ساعدوني

[فيزيائية متورطه]

two marbles of mass 2kg each are placed with thier centers 1.0m apart. what is the gravitational force of attraction between them?


Aforce of 20N acts on ababy and moves it 30m in the direction of force. calculate the work done?

[الأستاذ المحاضر]

by using the gravitational law :

http://upload.wikimedia.org/math/7/c/d/7cdf733b81cd2b83d434160241d6023c.png

http://upload.wikimedia.org/wikipedia/commons/thumb/0/0e/NewtonsLawOfUniversalGravitation.svg/300px-NewtonsLawOfUniversalGravitation.svg.png


we find:
http://latex.codecogs.com/gif.latex?\huge&space;F=\tfrac{G.2^{2}}{1^{2}}


and we have :

http://latex.codecogs.com/gif.latex?\huge&space;G=&space;6.67&space;.&space;10^{-11}

by calculate we find F

http://latex.codecogs.com/gif.latex?\huge&space;F=&space;26.68&space;.&space;10^{-11}&space;N

[الأستاذ المحاضر]

second question :

we have the law of the work of a force

http://latex.codecogs.com/gif.latex?\huge&space;w(F)=&space;F.d.cos(\alpha&space;)

the angle between the vector of force and the vector of the distence is 0

so :
http://latex.codecogs.com/gif.latex?\huge&space;cos(0)&space;=&space;1

so:

http://latex.codecogs.com/gif.latex?\huge&space;w(F)=&space;F.d

by caculating we find:

http://latex.codecogs.com/gif.latex?\huge&space;w(F)=&space;20.30

so:

http://latex.codecogs.com/gif.latex?\huge&space;w(F)=&space;600&space;joule


أرجو أن أكون صائبا ، بس يا ريت لو تكتب مشاركاتك بالعربية لأن هذا المنتدى عربي
:s_thumbup: