If the mass of the bob in a simple pendulum is increased to thrice its original mass and its length is made half its original length, then the new time period of oscillation is $\frac{x}{2}$ times its original time period. Then the value of $x$ is: |
$\sqrt{3}$ $\sqrt{2}$ $2\sqrt{3}$ 4 |
$\sqrt{2}$ |
The correct answer is option (2) : $\sqrt{2}$ The period of oscillation, $T$, of a simple pendulum is determined by the formula : $T=2\pi \sqrt{\frac{L}{g}}$ where : $L$ is the length of the pendulum $g$ is the acceleration due to gravity The mass of the bob does not factor into the equation for the period. Let's first denote the original length of the pendulum as $L$ and the original period of oscillation as $T_1$. Hence, $T_1=2\pi \sqrt{\frac{L}{g}}$ When the length of the pendulum is halved, the new length $L'$ would be $\frac{L}{2}$. Thus, the new period $T_2$ can be calculates as : $T_2=2\pi \sqrt{\frac{\frac{L}{2}}{g}}=2\pi \sqrt{\frac{L}{2g}}=2\pi \left(\frac{1}{\sqrt{2}}\right)\sqrt{\frac{L}{g}}=\frac{1}{\sqrt{2}}.2\pi \sqrt{\frac{L}{g}}=\frac{T_1}{\sqrt{2}}$ We are given that the new period $T_2$ is $\frac{x}{2}T_1$. Therefore, we can set up the equation : $\frac{T_1}{\sqrt{2}}=\frac{x}{2}T_1$ To din the value of $x$, we solve for $x$ : $\frac{1}{\sqrt{2}}=\frac{x}{2}$ Multiplying both sides by 2 : $\frac{2}{\sqrt{2}}=x$ Simplify to : $x= \sqrt{2}$ Hence, the correct answer is : Option 2: $\sqrt{2}$ |