# An object is thrown vertically from a height of #5 m# at # 8 ms^-1#. How long will it take for the object to hit the ground?

##### 1 Answer

Assuming the object is thrown downward, the time taken will be

#### Explanation:

The question doesn't specify whether the object is thrown upward or downward. I will assume it is thrown downward. This means that the initial velocity,

Use the formula

Rearranging into standard form for quadratic equations:

Use the quadratic formula or your preferred method of solving quadratic equations and take only the positive root:

(If the assumption was that the object was thrown upward instead, the initial velocity and the acceleration would have opposite signs: the initial velocity would be