Q146 / 160 · TS EAMCET 2015 · Physics

Sum of magnitude of two forces is $25 \mathrm{~N}$. The resultant of these forces is normal to the smaller force and has a magnitude of $10 \mathrm{~N}$. Then the two forces are

  • Correct answer
    A
    $14.5 \mathrm{~N}, 10.5 \mathrm{~N}$
  • B
    $16 \mathrm{~N}, 9 \mathrm{~N}$
  • C
    $13 \mathrm{~N}, 12 \mathrm{~N}$
  • D
    $20 \mathrm{~N}, 5 \mathrm{~N}$

Solution

Sum of two forces $F_1+F_2=25$ Resultant of these forces $(10)^2=F_1^2+F_2^2+2 F_1 F_2 \cos \theta$ Since, resultant is normal to the smaller force $\therefore \quad F_1+F_2 \cos \theta=0$ From Eqs. (i), (ii) and (iii), we get $\begin{gathered} F_1=14.5 \mathrm{~N} \\ F_2=10.5 \mathrm{~N} \end{gathered}$

Hence, the correct answer is option: 'A'.

Relevant Questions