The lowest point in Death Valley is 85.0 m below sea level. The summit of nearby Mt. Whitney has an elevation of 4420 m. What is the change in gravitational potential energy of an energetic 65.0 kg hiker who makes it from the floor of Death Valley to the top of Mt. Whitney?

Respuesta :

Answer:

The change in gravitational potential energy of the hiker = 2869685 J

Explanation:

Potential Energy: This is the energy possessed by a body, due to its change in position in the gravitational field. The unit of potential energy is Joules (J)

From the question,

Change in gravitational potential energy = Energy of the hiker at the top of  Mt. Whitney - Energy of the hiker at the floor of Death valley.

ΔEp = mgh₂ - mgh₁

ΔEp = mg(h₂-h₁)........................... Equation 1

Where ΔEp =  change in Potential Energy of the hiker, m = mass of the hiker, g = acceleration due to gravity, h₁ = lowest point in Death valley, h₂ = Elevation of Mt. Whitney.

Given: m = 65.0 kg, h₁ = -85 m ( because is a valley), h₂ = 4420 m,

Constant: g = 9.8 m/s²

Note: The h₁ is negative because is below sea level.

Substituting into equation 1

ΔEp = 65×9.8×[4420-(-85)]

ΔEp = 637(4420+85)

ΔEp = 637(4505)

ΔEp = 2869685

ΔEp = 2869685 J.

Thus the change in gravitational potential energy of the hiker = 2869685 J