The Velocity of a Sky Diver T Seconds After Jumping $v ( t ) = 80 \left( 1 - e ^ { - 02 t } \right)$

Multiple Choice

The velocity of a sky diver t seconds after jumping is given by $v ( t ) = 80 \left( 1 - e ^ { - 02 t } \right)$ . After how many seconds is the velocity 50 ft/s?

A) 5.0 s
B) 4.9 s
C) 8.9 s
D) 0.2 s
E) none of these