An object is thrown up into the air going 9m/s. how fast is it going 2 seconds later?

As per the question, the object is thrown in vertically upward direction.

The initial velocity of the ball [u] = 9 m/s.

We are asked to calculate the velocity of the ball after 2 second.

When the ball goes up, the only force that acts on the ball is the force of gravity.

Hence the acceleration of the ball is nothing else than acceleration due to gravity i.e g and it is downward in direction.

Here, it will be considered negative as it is downward in direction .

From equation of kinematics we know that-

                            v = u +at      [Here v is the final velocity and a is the acceleration.

                               = 9 +[-9.8]×2  m/s      

                               = 9-19.6

                               = -10.6 m/s

Here the negative sign indicates that the ball is falling downward. It is coming back after reaching its maximum height.

Here the total time of flight of the ball is-

If the ball is thrown from certain height from the ground, then the velocity of the ball will be the calculated value.

If the ball is thrown from the ground, obviously the ball will heat the ground after 1.8367 seconds later.So the velocity of the ball will be zero after 2 seconds.

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