The terminal velocity of a person falling through air is about 300Km/hr.The acceleration due to gravity is 10ms^-2.

The terminal velocity of a person falling through air is about 300Km/hr.The acceleration due to gravity is 10ms^-2. What C is in the equation 

v'=C[(g/C)-v], where g is the acceleration due to gravity and v is the velocity.

(a) How long does it take for a falling person to reach the 90 percent of this terminal velocity? 

t =  _____________

(b) How long to reach 95 percent? t =  __________

(c) How long to reach 99 percent? t =____________