During a painting process, a thin, flat tape of width b (dimension perpendicular to the
Channel: Doubtnut
Date: 2020-02-16

During a painting process, a thin, flat tape of width b (dimension perpendicular to the plane of the figure) is pulled through a paint filled channel of length L. The density and viscosity of the paint liquid is `rho` and `eta` respectively. The tape is pulled at a constant speed v and width of the channel is h. Find the minimum force needed to pull the tape.