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What is the angle between two forces of equal magnitude, #F_a# and #F_b#, when the magnitude of their resultant is also equal to the magnitude of either of these forces?

Answer 1

Isabella Alvarez

#theta=(2pi)/3#

Let the angle between #F_a and F_b# be #theta# and their resultant is #F_r# So

#F_r^2=F_a^2+F_b^2+2F_aF_bcostheta# Now by the given condition let #F_a=F_b=F_r=F#

Thus

#F^2=F^2+F^2+2F^2costheta#

#=>costheta=-1/2=cos(2pi/3)#

#:.theta=(2pi)/3#

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Answer 2

Isabella Alvarez

The angle between two forces of equal magnitude, F_a and F_b, when the magnitude of their resultant is equal to either force is 120 degrees.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.