# An object is thrown vertically from a height of #9 m# at # 6 m/s#. How long will it take for the object to hit the ground?

##### 2 Answers

The time to hit the ground is

#### Explanation:

Resolve in the vertical direction

The initial velocity is

The acceleration due to gravity is

The distance is

Applying the equation of motion

Solving this quadratic equation in

The time to hit the ground is

graph{4.9x^2-6x-9 [-9.99, 10.02, -5, 4.995]}

First, calculate the time the object takes to reach the maximum height.

To calculate the time taken to reach the maximum height, you have the following info:

According to the first equation of motion,

Plug in the values:

or,

or,

To reach the same height from where it was thrown (i. e.,

Thus, time taken to go up and come down to the

Now, all you need is the time taken by the object to go down the last

For that,

Use the third equation to get:

Plug in the values;

Now, find the time using the first equation of motion:

Thus, total time,

*hope that helped...Thanks for reading!!!*