Energy conversion

I'm sure this is quite fundamental for most in here but can somebody please
answer me this question ?

If energy cannot be created or destroyed and only converted. How come more
kinetic energy is produced when cycling rather than walking ? (and yet
walking requires more chemical energy than cycling)

In other words, if a walker and cyclist were side by side, they both pump
their legs the same amount of repetitions in order to move, the cyclists
would move further/faster than the walker.

Hiyas ,

Yes it is true that mass/energy is conserved. Since we have no nuclear
or atomic processes going on in your question, this reduces to the
Conservation of Energy.

Which states............

Ei = Ef [ the intial energy equals the final energy ]

or written out in more detail

.5mv^2 [ kinetic energy ] +mgh [ potential energy from gravity ] +
chemical energy + any other source of energy that is under consideration

= a constant ( some number which remains the same ).


This is a true statement..............................


Note that frictional losses occur and appear in the form of heat energy.

Best







?uzzled wrote in message
...
I'm sure this is quite fundamental for most in here but can somebody
please
answer me this question ?

If energy cannot be created or destroyed and only converted. How come more
kinetic energy is produced when cycling rather than walking ? (and yet
walking requires more chemical energy than cycling)

In other words, if a walker and cyclist were side by side, they both pump
their legs the same amount of repetitions in order to move, the cyclists
would move further/faster than the walker.

"?uzzled" wrote in message
...
I'm sure this is quite fundamental for most in here but can somebody
please
answer me this question ?

If energy cannot be created or destroyed and only converted. How come more
kinetic energy is produced when cycling rather than walking ? (and yet
walking requires more chemical energy than cycling)

In other words, if a walker and cyclist were side by side, they both pump
their legs the same amount of repetitions in order to move, the cyclists
would move further/faster than the walker.


Because of the bike's gearing the cyclist must pump harder but the trade off
is more distance covered.

Dave

Dear ?uzzled:

"?uzzled" wrote in message
...
I'm sure this is quite fundamental for most in here but can somebody
please
answer me this question ?

You've got two good responses so far...

If energy cannot be created or destroyed and only converted. How come
more
kinetic energy is produced when cycling rather than walking ?

Better mechanical advantage with the cycle. Less frictional losses. Less
"support losses" (the cyclist does not commonly support his entire weight
with his legs, so this muscle power is available for accelerating mass).

(and yet
walking requires more chemical energy than cycling)

Not necessarily true, but on a per-mile basis, yes.

In other words, if a walker and cyclist were side by side, they both pump
their legs the same amount of repetitions in order to move, the cyclists
would move further/faster than the walker.

You've got my two cents worth.

David A. Smith