Question

$A$ and$B$ are two like parallel forces. A couple of moment $H$ lies in the plane of $A$ and $B$ and is contained with them. The resultant of $A$ and $B$ after combining is displaced through a distance :

• A. $\frac{H}{A-B}$
• B. $\frac{H}{2(A+B)}$
• C. $\frac{H}{A+B}$
• D. $\frac{2H}{A-B}$

Answer 1

Answer: (C)

$\frac{H}{A+B}$

Answer 2

Let the resultant of A and B is displaced by x. Then change in net momentum of A and B = applied momentum $\therefore\quad Ax + Bx =H$ $\Rightarrow\quad x = \frac{H}{A+B}$