Water flows through a tube shown in figure. The areas of cross section at A and B are `1cm^2 and 0.5 cm^2` respectively. The height difference between A and B is 5cm. If the speed of water at A is 10 `cms^-1`. Find a. the speed at B and b. the difference in pressures at A and B.

Answer

A, B, C, D

Explanation

a. `vecV_Axxa_A=vecV_B=a_B`
`rarr 10xx1=vecV_Bxx0.5`
`rarr vecV_B=20cm/sec`
`b. 1/2rhov_A^2+rhogh_A+p_A`
`=1/2rhov_B^2+rhogh_A+p_B`
`rarr p_B-p_A=1/2rho(v_A^2-v_B^2)+rhog(h_A-h_B)`
`=1/2xx1(100-400)+1xx1000(5.0)`
`=-150+5000=4850Dyne/cm^2`
`485N/m^2`