Question

A parachutist of mass 100 kg falls from a height of 500 m. Under realistic conditions, she experiences air resistance. Based on what you know about friction, what can you say about the kinetic energy of the parachutist as she reaches the ground? Remember, 1 kJ = 1000 J. Acceleration due to gravity is g = 9.8 m/s2.

Answer 1

Answer:

$E_k=490\ kJ$

Explanation:

It is given that,

Mass of the parachutist, m = 100 kg

It falls from a height of 500 meters.

When the parachutist reaches the ground, the potential energy gets converted to its kinetic energy. The potential energy of the parachutist is given by the following formula as :

$E_p=E_k=m\times g\times h$

g is the acceleration due to gravity

$E_k=100\ kg\times 9.8\ m/s^2\times 500\ m$

$E_k=490000\ J$

Since, 1 kJ = 1000 J

So, $E_k=490\ kJ$

So, as the parachutist reaches ground its kinetic energy is equal to 490 kJ.

Answer 2

Given:
mass: 100 kg
height: 500 m
1 kJ = 1000 J
gravity = 9.8 m/s²

velocity before impact: v = √2gh ; v = √2 * 9.8 m/s² * 500 m ; v = 98.99494 m/s

KE = 1/2 m v²
KE = 1/2 * 100 kg * (98.99494 m/s)²
KE = 490,000 J

Pls. see attachment.