A burglar$\text{'}$s car had started with an acceleration of $2 m s^{-2}.$ A police vigilant party came after $5 s$ and continued to chase the burglar$\text{'}$s car with a uniform velocity of $20 m s^{-1}.$ The time $($in s$)$ taken in which the police van will catch the burglar$\text{'}$s car is: