A 0.20 kg mass is suspended from a spring - AQA - A-Level Physics - Question 14 - 2019 - Paper 1

The weight of the 0.10 kg mass is:

$W_{0.10} = 0.10 imes 9.81 = 0.981 ext{ N}$

This weight acts downward, and thus, it affects the tension in the thread that was supporting the 0.20 kg mass.

When the thread is cut, tension becomes zero, leading to the net force on the 0.20 kg mass being:

$F_{ ext{net}} = W_{0.20} - W_{0.10}$

Thus, substituting values:

$F_{ ext{net}} = 1.962 - 0.981 = 0.981 ext{ N}$

Using Newton’s second law, we calculate the acceleration:

0.981 = 0.20 a \ a = \frac{0.981}{0.20} = 4.905 ext{ m/s}^2$$ The upward acceleration of the 0.20 kg mass at the instant the thread is cut is approximately 4.9 m/s².