Equilibrium of a Rigid Body

A heavy chain, fixed at both ends is hanging as in fig(i). Now it is pulled in such a way that it forms a triangle as shown in figure (ii). Which of the following is correct?

.A uniform rod of$20 \mathrm{kg}$ is hanging in a horizontal position with the help of two threads. It also supports a$40 \mathrm{kg}$ mass as shown in the figure. Find the tensions developed in each thread.

 Three identical uniform rods each are acted on by two or more forces, all are perpendicular to the rods and all are equal in magnitude. Which of the rods could be in static equilibrium if an additional force is applied at the centre of mass of the rod ?

A metre scale is suspended vertically from a horizontal axis passing through one end of it. Its time period would be

If three bodies are in equilibrium as shown in figure then ratio of normal reaction on $A$ from wall to normal reaction on $C$ from the wall is independent of:
($m_B$ is mass of cone, $R_A$ is radius of sphere $A$, $R_B$ is radius of cone and ground is smooth.)

A uniform rod of mass $4 \mathrm{kg}$ is suspended using two equal length strings ($1$) and ($2$), tied at the end points $A$ and $B$ respectively. Length of rod is $100 \mathrm{cm}$. Another mass $2 \mathrm{kg}$ is suspended at $20 \mathrm{cm}$ from $A$ as shown. Under equilibrium conditions, tension in the left string, $T_1$ is: (Take $g=10 \mathrm{m} {\mathrm{s}}^{-2}$)

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The centre of mass of an extended body on the surface of the earth and its centre of gravity

A force $F$ is applied on the square block of edge length $2a$ such that the block remains stationary on the vertical wall. Then false statement is

Two uniform rods of equal length but different masser are rigidly joined to form an $L$-shaped body, which is then pivoted as shown in figure. If in equilibrium the body is in the shown configuration, ratio $M/m$ will be

A thin rod of mass $m_2$ and length $l$ is leaning on a block with a mass $m_1$ at angle $\alpha$ with the horizontal (see figure). What is maximum distance $S$ from $A$ upto which a person of mass $M$ at point $A$ can go on the rod keeping block in equilibrium. It is given that rod is fixed at point $A$ on ground. The coefficient of friction between block and ground is $\mu$.

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A rod $AB$, $2.5 \mathrm{m}$ long is supported at $A$ and $B$, the rod is carrying a point load of $5 \mathrm{kN}$ at a distance of $1 \mathrm{m}$ from $A$. What are the reaction at $A$ and $B$.

What is couple arm?

Explain a couple of forces?

What is couple in physics?

A uniform rod $AB$ of mass $M$ and length $L$ is suspended from four identical wires with two wires at end $B$, one at end $A$ and one at centre. Natural length of wires is ${\ell }_0$. Tensions in wires connected at $A$ is given by $\frac{Mg}{n}$. Find $n$. (Diagram is not drawn to scale)

Imagine a hole drilled along the radius of earth. A uniform rod of length equal to radius $R$ of earth is inserted into the hole. The distance of centre of gravity of the rod from the centre of earth is $\frac{n}{3}R$, find the value of $n$.

To form a couple, the force should be: 

Differentiate between centre of mass and centre of gravity.

Mechanical advantage $\left(MA\right)$,  Load $\left(L\right)$ and effort $\left(E\right)$ are related as :

Define moment of couple? Give example.