When the mass and speed of the body are doubled, the kinetic energy of the body

When the mass and speed of the body are doubled, the kinetic energy of the body
  1. becomes double
  2. becomes four times
  3. becomes eight times
  4. remains unchanged

Solution

Given that, the mass and speed of body are doubled. Then, final kinetic energy, $ \mathrm{KE}_f=\frac{1}{2}(2 m)(2 v)^2=\left(\frac{1}{2} m v^2\right) 8 $ where, $m$ and $v$ are initial mass and speed. Here, initial kinetic energy, $\mathrm{KE}_i=\frac{1}{2} m v^2$ $ \therefore \quad \mathrm{KE}_f=8 \mathrm{KE}_i $

Asked in: AP EAMCET 2021 (24 Aug Shift 1)

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