Question

Above is a diagram showing two masses hanging by a rope over a pulley of negligible mass. If friction is negligible, what is the magnitude of the acceleration of the masses?

• A. $3.3m/s^2$
• B. $9.8m/s^2$
• C. $4.9m/s^2$
• D. $5.0m/s^2$
• E. $2.9m/s^2$

Answer 1

The correct option is A $3.3m/s^2$

Given : $m_1=5$ kg $m_2=10$ kg

Let the tension and the acceleration of the masses be $T$ and $a$.

For 5 kg mass : $m_{1}a=T-m_{1}g$

For 10 kg mass : $m_{2}a=m_{2}g-T$

Adding these two we get $(m_1+m_2)a=(m_2-m_1)g$

$\therefore$ $(5+10)a=(10-5)\times 10$ $⟹a=3.3$ $m/s^2$