Velocity profile of a moving fluid over a flat (fixed) plate is given as: = from the fixed plate (yy = 0) in mm, u is the velocity in xx direction in mm/. Calculate the shear stress on the fluid at yy = 0.15 m if the viscosity of the fluid 8.6 poise (1 Poise= 1 yy.) 2

The question has some details missing which is the velocity profile .The velocity profile is given as u = (8y - 0.3y^2) mm/s

the shear stress on the fluid at y = 0.15 m = 6.80 x 10^-3N/m^2

Explanation:

The detailed steps is the use of the relationship between the shear stress, viscosity and the velocity profile. appropriate differentiation and substitution were made to calculate the shear stress as is shown in the attachment.

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.