Here is a way to measure an unknown mass m 2 without weighing it. A spring of negligible mass is squeezed between m 2 and a known mass m 1 = 3 kg . The system is laid on a frictionless table and

Question

Here is a way to measure an unknown mass $m_{2}$ without weighing it. A spring of negligible mass is squeezed between $m_{2}$ and a known mass $m_{1} = 3 kg$ . The system is laid on a frictionless table and released, as shown below. At a certain moment, the acceleration of $m_{1}$ is $a_{1} = - 2.20 m / s^{2}$ and the acceleration of $m_{2}$ is $a_{2} = 1.65 m / s^{2}$ . Find the value of $m_{2}$ (in kg).

Answer:

4

Solution:

The spring forces are internal, so $m_{1} a_{1} + m_{2} a_{2} = 0$

$m_{2} = - \frac{m _{1} a _{1}}{a _{2}} = \frac{3 \times 2.20}{1.65}$

$m_{2} = 4$ kg

TestHub · Accepted Answer

The spring forces are internal, so m 1 ​ a 1 ​ + m 2 ​ a 2 ​ = 0 m 2 ​ = − a 2 ​ m 1 ​ a 1 ​ ​ = 1.65 3 × 2.20 ​ m 2 ​ = 4 kg

Physics - NLM Question with Solution | TestHub

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