ExamBro
ExamBro
MHT CET · Physics · Mathematics in Physics

The angle between two forces of equal magnitude \(\mathrm{R}\), if the magnitude of their resultant is \(\frac{R}{2}\)

  1. A \(\cos ^{-1}\left(-\frac{7}{8}\right)\)
  2. B \(\cos ^{-1}\left(-\frac{5}{7}\right)\)
  3. C \(\cos ^{-1}\left(-\frac{3}{7}\right)\)
  4. D \(\cos ^{-1}\left(-\frac{3}{4}\right)\)
Verified Solution

Answer & Solution

Correct Answer

(A) \(\cos ^{-1}\left(-\frac{7}{8}\right)\)

Step-by-step Solution

Detailed explanation

\(\left(\frac{R}{2}\right)^{2}=R^{2}+R^{2}+2 R^{2} \cos \theta\)
\(\cos \theta=-\frac{7}{8}\)
\(\theta=\cos ^{-1}\left(\frac{-7}{8}\right)\)