A heavy iron bar, of weight mathrm{W} is having its one end on ground and other on shoulder of a per

English

Gujarati

Hindi

6.System of Particles and Rotational Motion

hard

A heavy iron bar, of weight $\mathrm{W}$ is having its one end on the ground and the other on the shoulder of a person. The bar makes an angle $\theta$ with the horizontal. The weight experienced by the person is:

A

$\frac{W}{2}$

B

$W$

C

$\mathrm{W} \cos \theta$

D

$\mathrm{W} \sin \theta$

(JEE MAIN-2024)

Solution

$R=$ net reaction force by shoulder

Balancing torque about pt of contact on ground:

$\mathrm{W}\left(\frac{\mathrm{L}}{2} \cos \theta\right)=\mathrm{R}(\mathrm{L} \cos \theta)$

$\Rightarrow \mathrm{R}=\frac{\mathrm{W}}{2}$

Standard 11

Physics

Share

Similar Questions

A thin rod $MN$, free to rotate in the vertical plane about the fixed end $N$, is held horizontal . When the end $M$ is released the speed of this end, when the rod makes an angle $\alpha $ with the horizontal, will be proportional to ( see figure)

hard

(JEE MAIN-2018)

In the figure, a ladder of mass $m$ is shown leaning against a wall. It is in static equilibrium making an angle $\theta$ with the horizontal floor. The coefficient of friction between the wall and the ladder is $\mu_1$ and that between the floor and the ladder is $\mu_2$. The normal reaction of the wall on the ladder is $N_1$ and that of the floor is $N_2$. If the ladder is about to slip, then
$Image$
$(A)$ $\mu_1=0 \mu_2 \neq 0$ and $N _2 \tan \theta=\frac{ mg }{2}$
$(B)$ $\mu_1 \neq 0 \mu_2=0$ and $N_1 \tan \theta=\frac{m g}{2}$
$(C)$ $\mu_1 \neq 0 \mu_2 \neq 0$ and $N _2 \tan \theta=\frac{ mg }{1+\mu_1 \mu_2}$
$(D)$ $\mu_1=0 \mu_2 \neq 0$ and $N _1 \tan \theta=\frac{ mg }{2}$

normal

(IIT-2014)

$A$ body is in equilibrium under the influence of a number of forces. Each force has a different line of action. The minimum number of forces required is

hard

A car wetghs $1800\; kg$. The distance between its front and back axles is $1.8\; m$. Its centre of gravity is $1.05\; m$ behind the front axle. Determine the force exerted by the level ground on each front wheel and each back wheel.

hard

A uniform disc with mass $M=4\,kg$ and radius $R=$ $10\,cm$ is mounted on a fixed horizontal axle as shown in figure. A block with mass $m =2\,kg$ hangs from a massless cord that is wrapped around the rim of the disc. During the fall of the block, the cord does not slip and there is no friction at the axle. The tension in the cord is_______ $N$

$\left(\right.$ Take $\left.g =10\,ms ^{-2}\right)$

hard

(JEE MAIN-2022)