A bicycle has a kinetic energy of 100 J. What kinetic energy would the bicycle have if it had one half of the mass and was moving with twice the speed?

###### Solution. Posted on Friday, May 15, 2015.

The formula of the kinetic energy is Ek = 0.5*m*v^2 , where m – a mass of the object (bicycle) and v – the velocity (speed) of the object.

Let’s compare between the initial kinetic energy and the final kinetic energy

The initial kinetic energy – Eki = 0.5*m*v^2

The final kinetic energy – Ekf = 0.5*(1/2*m)*(2*v)^2 = 2 * 0.5*m*v^2

Hence, we could see that the kinetic energy doubles. Ekf = 2*Eki or Ekf = 200 J.

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