I thought that the same amount of energy was needed to move a something no matter how you move it, the energy just gets displaced. Where does it get displaced when you ride a bike?
Sorry, my headphones died on my morning walk so I had time to think about this.
2006-08-07 03:35:48 · 10 answers · asked by thebuffettour 2 in Science & Mathematics ➔ Physics
The amount of energy needed to move an object is the force required to move it times the distance moved. Dragging an object across the ground takes a lot more energy than rolling it on wheels, though the end result is the same. The difference is the amount of energy required to overcome friction.
You are probably thinking about the energy needed to lift an object. When you lift something, it gains potential energy proportional to its mass and the height it's raised to. There too, though, the actual energy expenditure could be different depending on how much is lost to friction. When you're moving an object (or yourself) along a level path, all the work done is dissipated as friction etc., because there is no energy difference between the starting and ending position.
When you walk, some of your energy goes into lifting your legs, and friction with the ground. The bicycle is more efficient largely because it maintains momentum - once you get it moving, it will continue to roll along with relatively little friction loss.
2006-08-07 05:39:10 · answer #1 · answered by injanier 7 · 0⤊ 0⤋
This is kinda like the difference between energy and power. Say you want to raise a 100 kg weight up to the tenth floor (50 meters) of a building using a pulley. It will only take 50*100*9.8 J to raise it no matter how it is done. But what will require more power, raising it in 30 minutes or in 10 second? If you were raising it by hand, under which case would you be more tired? High power use tires us out more, so we say that we used more energy, even when we didn't!
So see, if you ride your bike as fast as you possibly can, you will be more tired than if you walked at a leisurely pace (or rode really slow).
2006-08-07 04:32:10 · answer #2 · answered by 1,1,2,3,3,4, 5,5,6,6,6, 8,8,8,10 6 · 0⤊ 0⤋
Energy spent or the work done in displacing a body = The force applied on the body x the displacement on the body.
So, if you walk 10m then cycle 10m, the work done in the 2 cases is different because the force needed to accelerate these 2 bodies are different.
2006-08-07 03:46:37 · answer #3 · answered by jimmy_siddhartha 4 · 0⤊ 0⤋
If you've ever walked and biked to the same place, you know that biking is easier and faster. It takes energy to walk, but none or little is required to coast. In either case, the energy expended is not in the moving of something [yourself] from here to there -- it is the friction and inertial losses involved in moving your legs.
2006-08-07 07:10:19 · answer #4 · answered by Anonymous · 0⤊ 0⤋
The difference between walking and cycling is all about friction. I don't have any proof for you but I imagine that the constant starting/stopping of your feet causes more friction than the continuous motion of pedaling and the rolling of your wheels.
The more friction there is the less efficient the method of travel and hence more energy would be required.
2006-08-07 03:47:12 · answer #5 · answered by Mike 5 · 0⤊ 0⤋
u spend less energy as u ride a bike, coz the bike converts the energy into mechanic and since the wheels are round then it has less/almost 0 friction against the road.
remember: energy is absolute!!!
2006-08-07 03:45:02 · answer #6 · answered by apc_nuke 4 · 0⤊ 0⤋
Less energy to ride a bike..
You should know this from practical experience..
2006-08-07 04:54:36 · answer #7 · answered by Anonymous · 0⤊ 0⤋
No, while cycling, more energy is lost.
2006-08-07 04:01:38 · answer #8 · answered by ag_iitkgp 7 · 0⤊ 0⤋
methinks you are confusing energy with work
2006-08-07 05:43:56 · answer #9 · answered by SteveA8 6 · 0⤊ 0⤋
in an ideal environment it would be the same
2006-08-07 06:27:56 · answer #10 · answered by smritish g 3 · 0⤊ 0⤋