# How much work does it take to raise a 7 kg  weight 23 m ?

Apr 3, 2018

It takes 1578 J.

#### Explanation:

By the principle of conservation of energy, the work done getting it up there is equal to the gain in gravitational potential energy.

The gain in gravitational potential energy is given by

$\Delta G P E = m \cdot g \cdot \Delta h = 7 k g \cdot 9.8 \frac{m}{s} ^ 2 \cdot 23 m = 1578 J$

I hope this helps,
Steve

Apr 4, 2018

$1577.8$ joules

#### Explanation:

The work done is given by the equation,

$W = F \cdot d$

• $F$ is the force in newtons

• $d$ is the distance moved in meters

And so, the force is the weight of the box, which is $7 \setminus \text{kg"*9.8 \ "m/s"^2=68.6 \ "N}$.

Therefore, the work done is:

$W = 68.6 \setminus \text{N"*23 \ "m}$

$= 1577.8 \setminus \text{J}$