Question

Calculate the potential energy in kJ of a human body (70 kg) possesses on top of the Empire State Building (1,250 ft tall).

Answer 1

Answer:

Potential energy = 261.633 kJ

Explanation:

The potential energy is the energy stored in an object due to its position above Earth's surface.

The potential energy formula is :

$E_{p} =m.g.h$

Where $E_{p}$ is the potential energy

m is the object mass

g is the gravity

and h is the height referred to a comparison plane

We start by converting the height in feets to meters

$h=1250ft=1250ft.\frac{0.3048m}{1ft} =381m\\h=381m$

$m=70kg$

and

$g=9.81\frac{m}{s^{2} }$

$E_{p} =(70kg).(9.81\frac{m}{s^{2} } )(381m)=261632.7 kg.\frac{m}{s^{2} } .m$

Where

$kg.\frac{m}{s^{2} } =N$

N is Newton

$N.m=J$

J is Joule. Joule is the energy unit

$E_{p} =261632.7 J$

We divide it by 1000 to obtain kJ

$261632.7 \frac{J}{1000} =261.633 kJ$