Question

Two dogs pull horizontally on ropes attached to a post; the angle between the ropes is 65.0. Dog exerts a force of 256 and dog exerts a force of 344 .

A) Find the magnitude of the resultant force.

B) Find the angle the resultant force makes with dog 's rope.


You can do this graphically, it is easy. Or use the law of cosines.

F^2= F1^2 + F2^2 -2F1*F2*cosTheta

Now for the angle, but you did not specify which dog's rope. Draw the diagram.

F1, then at the tip of F1, put F2. You should be able to find the angle between F1 and the third side by the law of sines.

Or graphically, you measure it.

Thank you .. I answered (A) and it's 508 N

but I didn't understand how to answer (B) could u please explain more ? ..

And quistion (B) required the angle between the resultant and dog A's rope ..

Answer 1

for B) arctan(y component/x component)

Answer 2

this foormula F^2= F1^2 + F2^2 -2F1*F2*cosTheta is wrong there is no minus in it.
thx