MCQ
$A$ weightless rod is acted on by upward parallel forces of $2N$ and $4N$ ends $A$ and $B$ respectively. The total length of the rod $AB = 3m$. To keep the rod in equilibrium a force of $6N$ should act in the following manner:
  • A
    Downwards at any point between $A$ and $B.$
  • B
    Downwards at mid point of $AB.$
  • C
    Downwards at a point $C$ such that $AC = 1m.$
  • Downwards at a point $D$ such that $BD = 1m.$

Answer

Correct option: D.
Downwards at a point $D$ such that $BD = 1m.$
d
Let $x$ be the distance of the action of the force on the rod at point $D$ from the $mid-point$ of the rod.

Net torque on the mid-point of the rod

$\Longrightarrow 2 \times 1.5+6 x=4 \times 1.5$

$\Longrightarrow 6 x=3$

$\Longrightarrow x=0.5 m$

So, the distance of the position of force from $A$ and $B$ will be $2 m$ and $1 m .$

Thus, the force will be downwards at $D$ such that $BD = 1$ $\mathrm{m}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

A force $F = Be^{-Ct}$ acts on a particle whose mass is $m$ and whose velocity is $0$ at $t = 0$. It’s terminal velocity is :
The fraction of a floating object of volume ${V_0}$ and density ${d_0}$ above the surface of a liquid of density $d$  will be
A body is thrown vertically upwards. Which one of the following graphs correctly represent the velocity vs time?
Vectors $a \hat{i}+b \hat{j}+\hat{k}$ and $2 \hat{i}-3 \hat{j}+4 \hat{k}$ are perpendicular to each other when $3 a+2 b=7$, the ratio of a to $b$ is $\frac{x}{2}$. The value of $x$ is $..............$
A car is moving with speed $30$ $m/\sec $ on a circular path of radius $500\, m$. Its speed is increasing at the rate of $2m/{\sec ^2},$ What is the acceleration of the car ........ $m/sec^2$
As shown in the figure, a particle is moving with constant speed $\pi\,m / s$. Considering its motion from $A$ to $B$, the magnitude of the average velocity is:
Two whistles $A$ and $B$ each have a frequency of $500\,\,Hz$. $A$ is stationary and $B$ is moving towards the right (away from $A$) at a speed of $50\,\, m/s$. An observer is between the two whistles moving towards the right with a speed of $25\,\, m/s.$ The velocity of sound in air is $350 \,\,m/s$. Assume there is no wind. Then which of the following statements are true:
A body starts from rest and moves with uniform acceleration for $3\ s.$ It then decelerates uniformly for $2\ s.$ and stops. If the deceleration is $3 \ ms^{-2}$ the maximum velocity of the body is$. . . ms^{-1}$
The driver of a car travelling at velocity $v$ suddenly see a broad wall in front of him at a distance $d$. He should
A satellite orbits around the earth in a circular orbit with a speed $v$ and orbital radius $r.$ If it losses some energy, then $v$ and $r$ changes as: