Three bricks each of length (L) and mass (M) are arranged as... | Physics | SolveeIt | Solveeit

Today, August 18

Question

Three bricks each of length $L$ and mass $M$ are arranged as shown from the wall. The distance of the centre of mass of the system from the wall is

A

$L/4$

B

$L/2$

C

$(3/2)L$

D

$(11/12)L$

Answer

$(11/12)L$

Explanation

Solution

${{x}_{1}}=\frac{L}{2}$
${{x}_{2}}=L$
${{x}_{3}}=L+\frac{L}{4}$
${{x}_{3}}=\frac{5L}{4}$
$\therefore$ ${{x}_{CM}}=\frac{{{m}_{1}}{{x}_{1}}+{{m}_{2}}{{x}_{2}}+{{m}_{2}}{{x}_{3}}}{3m}$
$=\frac{\frac{mL}{2}+mL+\frac{m5L}{4}}{3m}$
$=\frac{11L}{12}$