Question

A cylindrical jar of cross sectional area 0.05 m sq. is filled with water to a height of 50 cm which carries a tight piston of negligible mass. Calculate the pressure at the bottom of the jar when a mass of 10 kg is placed on piston.

(Take g = 10 metre per second square)

Answer 1

Pressure near the piston=force/area = mg/A =1*10/0.01 =1000pa Pressure at the bottom =10000+5000 =6000 pa

Answer 2

Heya pragya g.....     Area A =  0.05 m^2   height = 50 cm = 0.50 meter    Pressure due to atmospheric air = 1.013 * 10^5 Pa = 101,300 Pa Pressure on the surface of water = by the mass of 10kg         =   weight of 10kg/area of piston          = 1 0kg * 10 m/sec² / 0.05 m^2           = 2000  Pa    Pressure due to the water column (depth) of water at the bottom of the jar      = weight of water column / area of cross section        = ρ g h                (ρ is the density )        = 1000 kg/m³ * 10 m/sec² * 0.50 m        = 5000 pa      @skb