Question

An object with mass 0.5 kg, resting on a frictionless horizontal table, is connected to a cable that passes over a frictionless pulley and is then fastened to a hanging object with mass 0.2 kg.

 

Determine the tension in the cable.  

Answer 1

$$T=m_1a\\m_2g-T=m_2a\\T=\frac{m_2m_1}{m_1+m_2}g\\T=\frac{0.5\cdot 0.2}{0.5+0.2}9.8=1.4\ N$$