Ten fifty paise coins are placed on the top of each other on a horizontal table. If the mass of the each coin is m gm. Find the magnitude and direction of

i) the force on the 7th coin (counted from the bottom) due to

all the coins above it.

ii)the reaction of the 6th coin from the bottom on the 7th coin

from the bottom.

2)

Ten fifty paise coins are placed on the top of each other on a horizontal table. If the mass of the each coin is m gm. Find the magnitude and direction of

i) the force on the 7th coin (counted from the bottom) due to

all the coins above it.

ii)the reaction of the 6th coin from the bottom on the 7th coin

from the bottom.

If a force required just to move a body up an inclined plane is double the force required to prevent the body from sliding down, then find the angle of inclination θ of the plane in terms of co-efficient of friction μ.

3)

Prove that the maximum horizontal range is four times the maximum height attained by the projectile, when fired at an inclination so as to have maximum horizontal range.

4) A balloon is raising up vertically with a uniform velocity of 29m/s. a stone is released from it reaches the earth in 10 seconds after it is dropped. Find the height from which the stone when dropped. (g= 9.8m/s2).

5) At what angle two forces (P+Q) and (P-Q) act so that the resultant is √(3P2+Q2).

6) A body travels 200cm in the first two seconds and 220cm in the next four seconds. What will be the velocity at the end of the seventh second from start?

7) Obtain by the method of dimensional analysis an expression for the surface tension of a liquid rising in a capillary tube. Assume that the surface tension (force per unit length) depends on the mass m, pressure p of the liquid and radius r of a capillary tube. The constant K=1/2.