Question

Suppose a skydiver (mass = 75kg) is falling toward the earth. When the skydiver is 100m above the earth, he is moving at 60m/s. At this point, calculate the skydiver’s:

• Gravitational Potential Energy
• Kinetic Energy
• Total Mechanical Energy (kinetic + potential)

Answer 1

gravitational potential energy is given as

`PE = mgH`

here given that

m = 75 kg

g = 9.8

H = 100 m

now plug in all value above

`PE = 75 * 9.8* 100`

`PE = 73500 J`

now for kinetic energy we can use

`K = (1)/(2)mv^2`

here we have

m = 75 kg

v = 60 m/s

now we have

`K = (1)/(2)*75*60^2`

`K = 135000 J`

now for mechanical energy we have

`ME = KE + PE`

so now we will add above to energy to find mechanical energy

`ME = 73500 + 135000`

`ME = 208500 J`