(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Water flows at 7 m/s in a pipe of radius 5 cm. A plate having an area equal to the cross-sectional area of the pipe is suddenly inserted to stop the flow. Find the force exerted on the plate. Take the speed of sound in water to be 1.4 km/s. (Hint: When the plate is inserted, a pressure wave propagates through the water at the speed of sound v_{s}. The mass of water brought to a stop in time Δt is the water in a length of tube equal to v_{s}Δt.)

2. Relevant equations

P = F/A

3. The attempt at a solution

I am trying to attempt the problem in the following way: Consider a reference frame where the water is still. Then the insertion of the plate would actually be a plate moving at 7 m/s, causing the still water to start moving. However, I am not sure how to get the force from this. It's probably going to be from P = F/A. Can anyone help me get started on this problem?

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# Homework Help: Force on water inside pipe

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