A bus starts from rest with a constant acceleration of `5 m//s^(2)` at the same time a car travelling with a constant velocity `50 m//s` over takes and passes the bus. How fast is the bus travelling when they are side by side?
A. `10 m//s`
B. `50 m//s`
C. `100 m//s`
D. `150 m//s`