A mass of $2.9 \mathrm{~kg}$ is suspended from a string of length $50 \mathrm{~cm}$ and is at rest. Another…
- 145 N
- 135 N
- 125 N
- 90 N
Solution

$ \begin{array}{lc} & m_1 u_1+m_2 u_2=m_1 v_1+m_2 v_2 \\ u_1=0, u_2=150 \mathrm{~m} / \mathrm{s}, m_1=2.9 \mathrm{~kg} \text { and } m_2=0.1 \mathrm{~kg} \\ \text { So, } & 2.9 \times 150=(2.9+0.1) \mathrm{v} \\ \Rightarrow & \frac{2.9 \times 150}{3}=v \\ \Rightarrow & \\ \text { Also, } & T \sin \theta=\frac{m v^2}{r} \end{array} $ Putting the values and solving, we get $T=135 \mathrm{~N}$
Asked in: AP EAMCET 2013
Practice more Center of Mass Momentum and Collision questions on Aicharya