system
Given the following post, respond as if you're commenting on Reddit:
human
Why is it easier to walk uphill than to bike?

I got nerdsniped with this one today, and my knowledge of highschool physics is failing me. So I ask, why is it easier to go up a hill if I get off my bike and walk?
gpt
On a bike, you have to provide all of the force to keep the bike form rolling backwards down the hill *plus* all the force to move you forwards.  On foot, the force that prevents you from sliding backwards is provided by friction.