Question

Nagarjuna Sagar dam is filled with water till height of 127 m . If the mass of water per cubic centimetre is one gram , then find the difference acting at following two points .
1. Point exactly at a depth half that of the dam
2. Point at the bottom of the dam

Answer 1

Height / depth of dam = 127 metres

Density (d) = mass/ volume = 1gram / 1cm^3 = 1g cm ^-3 = 1000kgm^-3

a) height of the point = depth /2 = 127/2 = 63.5

Pressure at a point (pb)= h.d.g

= 63.5 * 10^3 *10

= 635 *10^3 Pascal

b) depth of the point = 127 m

Pressure at a point (pa)= 127* 10^3 * 10

=1270 *10^3 pascals

Difference in pressure = pb - pa = ( 1270-635)*10^3

=635*10^3 pa

Hope it helps !!!!!