Question 58: Centre of Mass and Rotational Motion

Question

The masses of 200 g and 300 g are attached to
the 20 cm and 70 cm marks of a light meter rod,
respectively. The moment of inertia of the
system about an axis passing through 50 cm
mark is

Accepted Answer

Given, $$m_1=200$$ g = 0.2 kg
$$m_2=300$$ g = 0.3 kg
$${l_1} = 50 - 20 = 30$$ cm
$$ \Rightarrow {l_1} = 0.3$$ m
$${l_2} = 70 - 50 = 20$$ cm = 0.2 m
$$	herefore$$ Moment of inertia of the system about an axis passing through 50 cm mark (i.e. mid-point)
$$I = {m_1}l_1^2 + {m_2}l_2^2$$
$$ = 0.2 	imes {(0.3)^2} + 0.3 	imes {(0.2)^2}$$
$$ = 0.036$$ kg m$$^2$$

Answer

0.15 kg m$$^2$$

Answer

0.036 kg m$$^2$$

Answer

0.3 kg m$$^2$$

Answer

Zero

Centre of Mass and Rotational Motion

The masses of 200 g and 300 g are attached to the 20 cm and 70 cm marks of a light meter rod, respectively. The moment of inertia of the system about an axis passing through 50 cm mark is

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