system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do bike gears change the amount of work you do but stay the same speed?
gpt
Changing gears doesn't change the amount of work you need to do. It changes the amount of force you need to apply to the pedals, but the trade-off is that you need to make more rotations to go the same speed. For instance, perhaps one gear has you making one revolution per second with a force of 100N, but lower gear might have you make 1.5 revolutions per second with a force of 67N, and a higher gear might have you make half a revolution per second, but will require a force of 200N.

Since work is the force multiplied by the distance, it's always the same, different gears just allow a different ratio of force to distance.