(adsbygoogle = window.adsbygoogle || []).push({}); Mechanics Part II :)

Hi.

Sorry, i got stuck again..

well...

Two Forces,PandQ, act on a particle. The forcePhas a magnitude 5N and the forceQhas magnitude 3N. The angle between the directions ofPandQis 40 degrees. The RESULTANT ofPandQisF

(a) Find, the magnitude ofF

(b) Find, in degrees to one decimal place the angle between the directions ofFandP.

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Now, my stab at part (a) was in the form

F^2 = Fx^2 + Fy^2

- = (5cos 40)^2 + (3sin 40)^2

However, it gives me a different answer to the mark scheme...

who have...(5+ 3cos40)^2+ (3 in 40)^2 .....

Why the 5 +3 cos40 ... i dont really get it...

Any help would be greatly appreciated.

(b) similarly for this.. my version would be ; tan(theta)= Fy / Fx ..but then for Fx... there would be 5+3cos 40... which i dont really understand how you get....

THANKS :)

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# Homework Help: Mechanics Part II

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