To determine whether the car can stop before hitting the dog, the stopping distance must be calculated using the formula $d = \frac{v^2}{2a}$, where $v$ is the initial velocity and $a$ is the deceleration. Given the braking force of 2000 N, the deceleration can be found using $F = ma$, resulting in an acceleration of $a = \frac{F}{m} = \frac{2000}{800} = 2.5 \, \mathrm{ms^{-2}}$. With an initial speed of $20 \, \mathrm{ms^{-1}}$, the stopping distance is $d = \frac{(20)^2}{2 \times 2.5} = 80 \, \mathrm{m}$, which means the car will stop 30 m after hitting the dog, as it is only 50 m away.