(Solved): The acceleration of a particular sports car is proportional to the difference between 250km/h an ...

The acceleration of a particular sports car is proportional to the difference between $$250\mathrm{km}/\mathrm{h}$$ and the velocity of this sports car. If this machine can accelerate from rest to $$120\mathrm{km}/\mathrm{h}$$ in $$11\mathrm{s}$$, how long will it take for the car to accelerate from rest to $$240\mathrm{km}/\mathrm{h}$$ ? It would take second(s). (Round to one decimal place as needed.)