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Physics · WORK, ENERGY AND POWER
हिन्दीThe kinetic energy of a \( 2000\text{ kg} \) car travelling at \( 25\text{ m s}^{-1} \) is \( K_C \). A running athlete of mass \( 70\text{ kg} \) has a speed of \( 10\text{ m s}^{-1} \) and kinetic energy \( K_A \). The ratio \( \frac{K_C}{K_A} \) is approximately:
Correct answer · Option 1
\( 180 \)
Explanation
\( K_C = \frac{1}{2}(2000)(25)^2 = 6.25\times 10^5\text{ J} \approx 6.3\times 10^5\text{ J} \). \( K_A = \frac{1}{2}(70)(10)^2 = 3.5\times 10^3\text{ J} \). Ratio \( = \frac{6.25\times 10^5}{3.5\times 10^3} \approx 178.6 \approx 180 \).
