Question

mass of Rod in the given question?​

Answer 1

Answer:

100 grams

Explanation:

Given :

• Mass of the suspended object = 80 grams = 0.08 kg
• The rod is equilibrium position even if the mass is suspended
• The centre of gravity is 14 cm away from A

To find:

• Mass of the rod

Distance at 14 cm away from A = 30 cm - 14 cm = 16 cm

Using moment rule:

Moment of the force = Force × distance

Substituting the values :

0.8×20=16×W

16 = 16 W

W = 16/16

W = 1 kg m/s^-2

So, W = 1000 Newtons

Here we need to find the mass and the weight is 1000 Newtons

Gravitational force = 10 m/s²

Mass = 1000/10

Mass = 100 grams

100 grams

Answer 2

Position of center of mass from the support edge,

$\displaystyle\longrightarrow\sf{x_1=30\ cm-14\ cm}$

$\displaystyle\longrightarrow\sf{x_1=16\ cm}$

Let $\displaystyle\sf {M}$ be mass of the rod.

Mass of the block suspended on the rod,

$\displaystyle\longrightarrow\sf{m=80\ mg}$

$\displaystyle\longrightarrow\sf{m=80\times10^{-3}\ g}$

$\displaystyle\longrightarrow\sf{m=0.08\ g}$

Its position from the support edge is $\displaystyle\sf {x_2=20\ cm.}$

Since the net rotational effect about the support edge is zero, we have,

$\displaystyle\longrightarrow\sf{Mx_1-mx_2=0}$

$\displaystyle\longrightarrow\sf{M=\dfrac {mx_2}{x_1}}$

$\displaystyle\longrightarrow\sf{M=\dfrac {0.08\times20}{16}}$

$\displaystyle\longrightarrow\underline {\underline {\sf{M=0.1\ g}}}$

$\displaystyle\longrightarrow\sf {\underline {\underline {M=100\ mg}}}$

Hence mass of the rod is $\displaystyle\bf {100\ mg.}$