Question

1.) Water flows from a 2 cm diameter pipe, at a speed of 0.35m/sec. How long will it take to fill a 10 liter container?

2.) A horizontal segment of pipe tapers from a cross-sectional area of 50 cm^2 to 0.5 cm? The pressure at the larger end of the pipe is 1.2x 10^5 Pa and the speed is 0.04m/sec. What is the pressure at the narrow end of the segment?

thanks. :)

Answer 1

1. Volume flow rate = (Area)(Velocity) = pi*2^2/4 V = pi cm^2* 35 cm/s = 110 cm^3/s
Amount filled = V = 10,000 cm^3 = Q t
t = V/Q = 10,000 cm^2/(110 cm^3/s)
= ? s

2. Use the incompressible continuity equation V*A = constant to get the velocity at the narroqw end. Velocity will be 100 times higher at the narrow end. Then apply Bernoulli's equation for the pressure change.
P + (1/2)*(density)*V^2 = constant
P2 - P1 = (1/2)(density)(V1^2 - V2^2)

Answer 2

thanks for your help. :)