Question

In the figure $m_1$ and $m_2(m_1<m_2)$ are joined together by a pulley. When the mass $m_1$ is released from the height $h$ above the floor, it strikes the floor with speed

(Given: Acceleration due to gravity $=g$)

• A. $\sqrt{2gh\left(\frac{m_1-m_2}{m_1+m_2}\right)}$
• B. $\sqrt{2gh}$
• C. $\sqrt{\frac{2m_{2}gh}{m_1+m_2}}$
• D. $\sqrt{\frac{2m_{1}gh}{m_1+m_2}}$

Answer 1

Answer: (A)

$\sqrt{2gh\left(\frac{m_1-m_2}{m_1+m_2}\right)}$

$E_i=E_f$

$0=m_{2}gh-m_{1}gh+\frac{1}{2}(m_1+m_2)v^2$

$\therefore v=\sqrt{2gh\left(\frac{m_1-m_2}{m_1+m_2}\right)}$