JEE Mains · Physics · STD 11 - Newtons laws of motion
- JEE Mains 2014
- Medium
- MCQ
Water is flowing at a speed of \(1.5\, ms^{-1}\) through a horizontal tube of cross-sectional area \(10^{-2}\, m^2\) 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 ......... \(N\) (density of water \(= 10^3\, kgm^{-3}\))
Pick an option to check your answer.
Answer & Solution
Correct Answer
(A) \(22.5\)
Step-by-step Solution
Detailed explanation
\(F=v \frac{d m}{d t}\)
\(=v A \rho v\)
\(=v^{2} A \rho\)
\(=(1.5)^{2} \times 10^{-2} \times 10^{3}\)
\(=2.25 \times 10=22.5 N\)
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