. Ten one rupee coins each of mass m are placed on the top of each other. If coins are counted
from the bottom then calculate the force exerted by 8
th coin on the 7th coin.
Answers
Answer:
a) Force on the seventh coin is exerted by the weight of the three coins on its top.Weight of one coin = mg
Weight of three coins = 3mg
Hence, the force exerted on the 7th coin by the three coins on its top is 3mg. This force acts vertically downward.
(b) Force on the seventh coin by the eight coin is same as the Force on the 7th coin due to top three coins.
(c) The 6th coin experiences a downward force because of the weight of the four coins (7th, 8th, 9th, and 10th) on its top.
Therefore, the total downward force experienced by the 6th coin is 4mg.
As per Newtons third law of motion, the 6th coin will produce an equal reaction force on the 7th coin, but in the opposite direction. Hence, the reaction force of the 6th coin on the 7th coin is of magnitude 4mg. This force acts in the upward direction.