# An object is thrown vertically from a height of #2 m# at #18 m/s#. How long will it take for the object to hit the ground?

##### 1 Answer

#### Answer:

The time taken for the object to hit the ground is

#### Explanation:

Apply the equation of motion

The initial velocity is

The acceleration due to gravity is

Resolving in the vertical direction

The distance travelled is

Therefore,

Solving this quadratic equation for

The discriminant is

Therefore,

Therefore,

The time taken for the object to hit the ground is