Explanation:
Let upper direction be positive
We have equation of motion v = u + at
Initial velocity, u = 11 m/s
Final velocity, v = ?
Time, t = 2 s
Acceleration,a = -9.81 m/s²
Substituting
v = u + at
v = 11 + -9.81 x 2
v = -8.62 m/s
Speed of ball after 2 seconds is 8.62 m/s downward.
