# How much work does it take to raise a 9 kg  weight 9 m ?

Mar 6, 2018

$793.8 J$

#### Explanation:

Here work will be done against the gravitational force,which supplies the required amount of potential energy for the weight to be $9 m$ above the ground.

So,work done=$m g h = 9 \cdot 9.8 \cdot 9 = 793.8 J$

Mar 7, 2018

$\text{793.8 Joule}$

#### Explanation:

$\text{Work = Change in Potential energy}$

$W = {U}_{f} - {U}_{i}$

$W = {\text{mgh"_f - "mgh}}_{i}$

$W = \text{mg} \left({h}_{f} - {h}_{i}\right)$

W = "9 kg" × "9.8 m/s"^2 × ("9 m" - "0 m")

$W = \text{793.8 Joule}$