- #1
chengbin
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Allie, Beth, and Cathy are having a 3 way tug of war. Allie is pulling with a force of 30N, Beth with 50N, and Cathy with 70N. If the system is in equilibrium, what is the angle between Allie's rope and Beth's rope.
I used the cosine law, and
cos\theta=\frac{{30}^2+{50}^2-{70}^2}{2\cdot 30\cdot 50}
\theta = 120
But the answer is 60, because 180-120=60. Why?
I used the cosine law, and
cos\theta=\frac{{30}^2+{50}^2-{70}^2}{2\cdot 30\cdot 50}
\theta = 120
But the answer is 60, because 180-120=60. Why?
