A cubic block of side L and mass M is dragged over an oil

A cubic block of side L and mass M is dragged over an oil film across table by a string connects to a hanging block of mass m as shown in figure. The Newtonian oil film of thickness h has dynamic viscosity μ and the flow condition is laminar. The acceleration due to gravity is g. The steady state velocity V of block is

τ = μ		du
		dy

du = V – O – V
dy = h

τ = u	V	...(1)
	h

Also , τ =	F
	A

where F = mg , A = L²

∴ τ =	mg	......(2)
	L²

By (1) (2), we get

V =	mgh
	uL²

Severity: Notice

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Line Number: 268

Backtrace:

Severity: Warning

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Backtrace:

	Mgh
	μL²

	Mgh
	μ

	mgh
	μL²