A right triangular plate ABC of mass m is free to rotate in the vertical plane about a fixed horizontal axis through A . It is supported by a string such that the side AB is horizontal. The reaction at the support A is

Question

A right triangular plate ABC of mass m is free to rotate in the vertical plane about a fixed horizontal axis through A . It is supported by a string such that the side AB is horizontal. The reaction at the support A is <img class="img-fluid question-image" alt="Question" src="https://cdn.tardigrade.in/q/nta/p-p0xawsfyvszp.png" /> (A) (m textg/3) (B) ( text2 m textg/3) (C) (m textg/2) (D) m textg

Tardigrade Admin · Accepted Answer

For equilibrium of torque about A, (m textg)(l/3)=T(l) textorT=(m textg/3) For verticle equilibrium of plate, R textA+T=m textg∴ textR textA=(2 m textg/3)

Q. A right triangular plate $A BC$ of mass $m$ is free to rotate in the vertical plane about a fixed horizontal axis through $A$ . It is supported by a string such that the side $A B$ is horizontal. The reaction at the support $A$ is

$\frac{m g}{3}$

$\frac{2 m g}{3}$

$\frac{m g}{2}$

$m g$

For equilibrium of torque about A,
$(m g) \frac{l}{3} = T (l) or T = \frac{m g}{3}$
For verticle equilibrium of plate,
$R_{A} + T = m g ∴ R_{A} = \frac{2 m g}{3}$

Q. A right triangular plate ABC of mass m is free to rotate in the vertical plane about a fixed horizontal axis through A . It is supported by a string such that the side AB is horizontal. The reaction at the support A is

3mg​

32mg​

2mg​

mg