# Energy Confusion (Conservation of Energy?)

Anyone know if the following statement is true (and why)?

"Getting to higher ground would increase his gravitational potential energy, decreasing the effects of non-conservative forces, which would allow him to move easier."

CLARIFICATION: "move easier" refers to a lack of friction and not the slight increase in gravitational force. Do with that what you will.

Last edited:

sophiecentaur
Gold Member
Hmmm. I can't think what would "allow him to move easier" as g on higher ground is almost undetectably different from g at sea level.
Where did you find that statement?

• CWatters
Dale
Mentor
2021 Award
Getting to higher ground would increase his gravitational potential energy
This part is true

decreasing the effects of non-conservative forces, which would allow him to move easier
This part seems weird, like it was written by a drunk physicist.

• Jehannum, phinds and russ_watters
CWatters
Homework Helper
Gold Member
Friction actually makes it easier to move. If there was no friction driving and walking would be impossible.

Anyone know if the following statement is true (and why)?

"Getting to higher ground would increase his gravitational potential energy, decreasing the effects of non-conservative forces, which would allow him to move easier."

CLARIFICATION: "move easier" refers to a lack of friction and not the slight increase in gravitational force. Do with that what you will.
Do you mean friction or air-resistance? The air resistance is dependent on the density of air, which does decrease with increasing height. However, in practice a person would have to account for the fact that there would be less oxygen present due to the lower pressure.

The frictional force is, to a first approximation, usually given by f=μN, where μ is the coefficient of friction and N is the normal force.
Since N in many cases is opposing the gravitational force acting on the object, a change in g could result in a change of friction with height, but as @sophiecentaur noted, the rate at which g varies with height is small (the difference between g at sea level and a height corresponding to the top of Mount Everest can be calculated to be about 0.03 ms-2, even at the ISS, g is about 0.9 times that at sea-level), so in practice there would be little variation in friction.

• CWatters