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What is the ratio between the initial and final kinetic energies of a car, if its velocity is increased by four times?
1:8
1:7
1:16

Respuesta :

Let initial velocity be v

So

initial kinetic energy

  • KE=1/2mv²

Final velocity is four times v i.e 4v

Final kinetic energy

  • KE=1/2m(4v)²
  • KE=1/2m(16v²)

Find ratio

  • 1/2m(16v²):1/2mv²
  • 16v²:v²
  • 16:1

Or

  • 1:16

Option C

#BBH

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