4 ms·
>Wind resistance increases with the square of the speed. To be pedantic, wind resistance varies with the cube of the speed. That's my recollection and seems to
by HankB99 8y ago
>Wind resistance increases with the square of the speed.
To be pedantic, wind resistance varies with the cube of the speed. That's my recollection and seems to be used in the formula used to calculate power required at https://www.exploratorium.edu/cycling/aerodynamics1.html https://www.exploratorium.edu/cycling/aerodynamics1.html.
- mrob 8y agoDrag force does vary with the square of the speed, but power needed to overcome that drag force varies with the cube of the speed. From Wikipedia[0]: "Note that the power needed to push an object through a fluid increases as the cube of the velocity. A car cruising on a highway at 50 mph (80 km/h) may require only 10 horsepower (7.5 kW) to overcome aerodynamic drag, but that same car at 100 mph (160 km/h) requires 80 hp (60 kW).[16] With a doubling of speed the drag (force) quadruples per the formula. Exerting 4 times the force over a fixed distance produces 4 times as much work. At twice the speed the work (resulting in displacement over a fixed distance) is done twice as fast. Since power is the rate of doing work, 4 times the work done in half the time requires 8 times the power." Power output is directly felt by the rider, so it's the more relevant comparison here, and your comment is more practically useful. [0] https://en.wikipedia.org/wiki/Drag_(physics)#Power https://en.wikipedia.org/wiki/Drag_(physics)#Power
- HankB99 8y agoOh... right. Work done is force * distance so distance varies linearly with speed.