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JEE Main 2023 (13 Apr, Shift 2) · Kinetic Energy & Momentum

Kinetic Energy & Momentum question from JEE Main 2023 (13 Apr, Shift 2)

Q8JEE Main 2023 · 13 APR · SHIFT 2Easy

Kinetic Energy & Momentum

A car accelerates from rest to u m/su\text{ m/s}. The energy spent in this process is E J. The energy required to accelerate the car from u m/su\text{ m/s} to 2u m/s2u\text{ m/s} is nE JnE\text{ J}. The value of nn is ____________.

Numerical answer type. Work it out, then open the answer.

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Answer: 3

  1. Energy spent = gain in KE.
  2. 0→u0 \to u: E=12mu2E = \frac{1}{2}mu^2
  3. u→2uu \to 2u: 12m(4u2−u2)=3×12mu2=3E\frac{1}{2}m(4u^2 - u^2) = 3 \times \frac{1}{2}mu^2 = 3E
  4. n=3n = 3
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