Question

Two masses $m_1=4kg$ and $m_2=2kg$ are released from rest as shown in figure. Find
(i) The distance travelled b centre of mass in $9s$
(ii) The speed of centre of mass after $9S$

Answer 1

Given, Two masses $M_1=4kg,m_2=2kg$

So the net force at the point is:

$F=m_{1}g-m_{2}g=4g-2g=2\times 10=20N$

Acceleration on the center of mass is:

$a=\frac{F}{m_1+m_2}=\frac{20}{2+4}=\frac{10}{3}m/s^2$

a) Distance traveled in $9s$

$S=\frac{1}{2}a{t}^2=\frac{1}{2}\times \frac{10}{3}\times 9^2=135m$

b) The Speed of the CoM in $9s$

$V=at=\frac{10}{3}\times 9=30m/s$