1. A hammer exerts a force of 1.5 N on each of the two nails A and B. The area of cross section of tip of nail A is 2 mm2 while that of nail B is 6 mm2. Calculate pressure on each nail in pascal. Ans. On A : 7.5 x 105 pascal, On B : 2.5 x 105 pascal.
2. A block of iron of mass 7.5 kg and of dimensions 12 cm x 8 cm x 10 cm is kept on a table top on its base of side 12 cm x 8 cm. Calculate : (a) thrust and (b) pressure exerted on the table top. Take 1 kgf = 10 N. Ans. (a) 75 N (13) 7812.5 Pa
3. A vessel contains water up to a height of 1.5 m. Taking the density of water 103 kg 110, "acceleration due to gravity 9.8 m s-2 and area of base of vessel 100 cm2, calculate : (a) the pressure and (b) the thrust, at the base of vessel. Ans. (a) 1.47 x 104 N m2 (b) 147 N
4. The area of base of a cylindrical vessel is 300 cm2. Water (density = 1000 kg m-3) is poured into it up to a depth of 6 cm. Calculate : (a) the pressure and (b) the thrust of water on the base. (g = 10 m s2). Ans. (a) 600 Pa, (b) 18 N
5. (a) Calculate the height of a water column which will exert on its base the same pressure as the 70 cm column of mercury. Density of mercury is 13.6 g cm-3. (b) Will the height of the water column in part (a) change if the cross section of the water column is made wider ? Ans. (a) 9.52 m (b) No
A gas 'X' is collected over water at 17° C and 750 mm pressure. If the volume of the gas collected is 50cc, calculate the volume of the dry gas at STP [ at 17°C the vapour pressure of water is 14mm]
