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AP EAMCET · PHYSICS · Work Power Energy

Two bodies A and B of masses 20 kg and 5 kg respectively are at rest. Due to the action of a force of 40 N separately, if the two bodies acquire equal kinetic energies in times \(t_A\) and \(t_B\) respectively, then \(t_A: t_B=\)

  1. A \(1: 2\)
  2. B \(2: 1\)
  3. C \(2: 5\)
  4. D \(5: 6\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(2: 1\)

Step-by-step Solution

Detailed explanation

\(K = \frac{F^2 t^2}{2m}\) \(\frac{F^2 t_A^2}{2m_A} = \frac{F^2 t_B^2}{2m_B}\) \(\frac{t_A^2}{m_A} = \frac{t_B^2}{m_B}\) \(\frac{t_A}{t_B} = \sqrt{\frac{m_A}{m_B}}\) \(\frac{t_A}{t_B} = \sqrt{\frac{20}{5}}\) \(\frac{t_A}{t_B} = \sqrt{4} = 2\) \(t_A: t_B = 2:1\)