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JEE Main 20257 AprilEvening Shift
Exam
JEE Main
Year
2025
Date
7 April
Shift
Evening Shift
Subject
Physics
Chapter
Laws of Motion

JEE Main 2025 · 7 April · Evening Shift · Physics · Laws of Motion

An object with mass 500 g moves along x -axis with speed v=4 x ~m /...

An object with mass 500 g moves along x -axis with speed v=4x m/sv=4 \sqrt{x} \mathrm{~m} / \mathrm{s}. The force acting on the object is :

Options

  1. A8 N
  2. B5 N
  3. C6 N
  4. D4 N

Correct answer

D. 4 N

Step-by-step solution

F=M×av=4xv2=16x2vdvdx=16vdvdx=162=8F=0.5×8=4N\begin{aligned} & F=M \times a \\ & v=4 \sqrt{x} \\ & v^2=16 x \\ & 2 v \frac{d v}{d x}=16 \\ & \frac{v d v}{d x}=\frac{16}{2}=8 \\ & F=0.5 \times 8=4 N\end{aligned}
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