Question 688: Centre of Mass and Rotational Motion

Question

Three particles, each of mass m gram, are situated at the vertices of an equilateral triangle ABC of side $$l$$ cm (as shown in the figure). The moment of inertia of the system about a line AX perpendicular to AB and in the plane of ABC, in gram-cm
2
units will be

Accepted Answer

I
AX
= m(AB)
2
+ m(OC)
2
= m$$l$$
2
+ m ($$l$$ cos 60ÃÂº)
2
= m$$l$$
2
+ m$$l$$
2
/4 = 5/4 m$$l$$
2

Answer

$${3 \over 4}$$m$$l$$
2

Answer

2m$$l$$
2

Answer

$${5 \over 4}$$m$$l$$
2

Answer

$${3 \over 2}$$m$$l$$
2

Centre of Mass and Rotational Motion

Three particles, each of mass m gram, are situated at the vertices of an equilateral triangle ABC of side $l$ cm (as shown in the figure). The moment of inertia of the system about a line AX perpendicular to AB and in the plane of ABC, in gram-cm 2 units will be

Choose the correct answer: