If a ball is thrown vertically upwards with a velocity of

If a ball is thrown vertically upwards with a velocity of 40 m/s, then velocity of the ball after two seconds will be (g = 10 m/s²)

Initial velocity (u) = 40 m/s
Acceleration a = –g m/s² = –10 m/s²
Time = 2 seconds
By Ist equation of motion,
v = u + at
v = 40 – 10 (2) = 20 m/s