JEE Main 2014PhysicsLaws of MotionMediumMCQ

JEE Main 2014 — Laws of Motion Question with Solution

JEE Main 2014 (09 Apr Online)

Question

Water is flowing at a speed of 1.5 m s-1 through a horizontal tube of cross-sectional area 10-2 m2 and you are trying to stop the flow by your palm. Assuming that the water stops immediately after hitting the palm, the minimum force that you must exert should be (density of water = 103 kg m-3)

Choose an option

Show full solutionCorrect option: D
Correct answer
D22.5 N

Step-by-step explanation

υ = 1.5 m/s      A = 1 0 - 2 m 2

Now, F = d dt P

            = d dt m υ = υ dm dt

            = A υ · ρ · υ

            = A ρ υ 2

            = 1 0 - 2 × 1 0 0 0 × 1.5 2

            = 1 0 - 2 × 1 0 0 0 × 2.25

            = 22.5 N

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About this question

This is a previous-year question from JEE Main 2014, covering the Laws of Motion chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.