Ten one-rupee coins are put on top of each other on a table. Each coin has a mass $m$ Give the magnitude and direction of
$(a)$ the force on the $7^{\text {th }}$ coin (counted from the bottom) due to all the coins on its top.
$(b)$ the force on the $7^{\text {th }}$ coin by the elghth coin,
$(c)$ the reaction of the $6^{\text {th }}$ coin on the $7^{\text {th }}$ coin.
$(a)$ Force on the seventh coin is exerted by the weight of the three coins on its top.
Weight of one coin $=m g$
Weight of three coins $=3\, mg$
Hence, the force exerted on the $7^{\text {th }}$ coin by the three coins on its top is $3$ $mg$. This force acts vertically downward.
$(b)$ Force on the seventh coin by the eighth coin is because of the weight of the eighth coin and the other two coins (ninth and tenth) on its top.
Weight of the eighth coin $=m g$
Weight of the ninth coin $=m g$
Weight of the tenth coin $=m g$
Total weight of these three coins $=3\, m g$
Hence, the force exerted on the $7^{\text {th }}$ coin by the eighth coin is $3$ $mg$. This force acts vertically downward.
$(c)$ The $6^{\text {th }}$ coin experiences a downward force because of the weight of the four coins $\left( {{7^{th}}} \right){\rm{ }}$.
$8^{\text {th }}, 9^{\text {th }},$ and $10^{\text {th }}$ on its top.
Therefore, the total downward force experienced by the $6^{\text {th }}$ coin is $4 \,m g$.
As per Newton's third law of motion, the $6^{\text {th }}$ coin will produce an equal reaction force on
the $7^{\text {th }}$ coin, but in the opposite direction. Hence, the reaction force of the $6^{\text {th }}$ coin on the $7^{\text {th }}$ coin is of magnitude $4 \,mg$. This force acts in the upward direction.
A mass of $100\,kg$ is moved with uniform velocity under the influence of force $F$, then the force acting on the beam due to string connected to the ceiling ............ $N$
What will be the acceleration of blocks and tension in the string connecting the blocks $2\,kg$ and $5\,kg$ for the given figure :-
A jet of liquid of cross-sectional area $'a'$ strikes a wall making angle $\theta $ with wall. The water strikes with the wall with velocity $v$ and rebounds elastically. If density of liquid be $\rho $, the normal force on the wall is
Figure shows $(x,\, t)$, $(y,\, t)$ diagram of a particle moving in $2-$ dimensions.
If the particle has a mass of $500\,g$, find the force (direction and magnitude) acting on the particle.
Write condition of equilibrium when three force act on a particle.