Technician a says that when two cars hit head-on at 50 mph its like hitting a brick wall at 100 mph. technician b disagrees and says its like hitting a brick wall at 50 mph. who is correct?

Amixture of slurry and mud is to be pumped through a horizontal pipe of diameter 500 mm. the fluid behaves as a bingham plastic with a yield stress of 30 pa and viscosity 0.04 pa.s. describe the effects of the shear stress through a transverse section of the pipe by plotting the variation in shear stress and velocity profile: (i) just before the slurry starts to move (ii) as the slurry flows when the pressure gradient is double that in part (i)