Force of Gravity of Al on Mt. Everest

[thelightsare]

Homework Statement

In this problem find the force of gravity of Al. Al is standing at the top of Mt. Everest at an elevation of 8,848 m. Al has a mass of 58 kg. The Earth has a mass of 5.97e24 and a radius of 6.38e6m. What is the force of gravity acting on Al?

Homework Equations

F = GMm/r^2

The Attempt at a Solution

the dist. used to find F is from Al to the Earth's center ?
so r = 8848+6.38e6 ?
then plug in values

F = G 58(5.97e24)/(8848+6.38e6)^2
F$$\approx$$569.385 N?

Is this right? I feel like I'm missing soemthing

 

[PhanthomJay]

Homework Statement

In this problem find the force of gravity of Al. Al is standing at the top of Mt. Everest at an elevation of 8,848 m. Al has a mass of 58 kg. The Earth has a mass of 5.97e24 and a radius of 6.38e6m. What is the force of gravity acting on Al?

Homework Equations

F = GMm/r^2

The Attempt at a Solution

the dist. used to find F is from Al to the Earth's center ?
so r = 8848+6.38e6 ?
then plug in values

F = G 58(5.97e24)/(8848+6.38e6)^2
F$$\approx$$569.385 N?

Is this right? I feel like I'm missing soemthing

Hi, welcome to PF! Your equation is correct, but perhaps the values you are using are a bit off, since Al would weigh about 569 N at sea level, (more or less, depending on variabilities in Earth's radius, etc), then he should weigh a wee bit less atop the Mount. But in terms of significant figures, essentially, he weighs pretty much about the same on top as he does at the bottom.

 

[thelightsare]

Hi! Thanks you for the welcome and your help. And just for reassurance, for r was i right to add the two values together?

 

[PhanthomJay]

Hi! Thanks you for the welcome and your help. And just for reassurance, for r was i right to add the two values together?

Yes, the distance apart is measured to Earth's center.

 

[thelightsare]

Thanks so much!