2006-09-25 06:08:51 · 17 answers · asked by NICOLA L 1 in Science & Mathematics ➔ Physics
All of the processes in the cell depend on energy. Energy is used to pump the heart, to send nerve impulses, and to do any kind of work.
2006-09-25 06:13:21 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Energy is the capacity to move things (to do work) or cause a change. Note it is "capacity" for doing work or cause a change; it is not the actual doing work or changing something. Energy is a potential for doing.
Heat energy, for example, can change water into steam. Electrical energy can change cold metal into hot glowing light filaments. Chemical energy can change a log into a warm, toasty fire and ash. Atomic energy can change atoms into heat. And electrical-chemical energy can change neuron connections into thought. Bio-chemical energy can fuel your own ability to do work (move things).
None of these examples will actually happen if work is not done however. So the energy (the potential) has to be harnessed (controlled) and focused on the work to be done. That is, the energy is lost to useful work or change if there is no system to use that energy for the work or change.
Properly harnessed, energy generates force, and force causing movement over a distance is work. For example, heat energy generated by chemical change (the burning fuel) is converted to thrust (force) in a rocket, which moves over a distance and that is work.
One thing I would like to mention...so called "potential" energy. In the physics books you'll see mgh = E as the potential energy of a body with mass m at a height h above some reference point. I, for one, do not believe potential energy is really an energy.
For one thing, the term "potential energy" is like saying potential potential capacity. It is redundant.
For another, it is the kinetic energy generated when the body is dropped that is the potential capacity for doing work. If anythiing, potential energy is the capacity for becoming potential capacity to do work or cause a change. In other words, potential energy is not true energy because it is one step removed from the capacity to do work or cause a change.
Over the years, I've discovered one important thing. Scientists and engineers are not very good at defining terms that are consistent with logic.
2006-09-25 06:53:08 · answer #2 · answered by oldprof 7 · 0⤊ 0⤋
DUH
We need energy to move for example
2006-09-25 06:17:21 · answer #3 · answered by god0fgod 5 · 0⤊ 0⤋
The energy you consume in your activities (walking, thinking, etc) has to be replaced or your body will run down like a dead battery.
2006-09-25 06:26:20 · answer #4 · answered by ideogenetic 7 · 0⤊ 0⤋
Come on. It's obvious. How will you beable to function? It's simple. Without Energy there would be No you.
2006-09-25 06:19:56 · answer #5 · answered by jacquelinewalker_22@verizon.net 1 · 0⤊ 0⤋
you need energy for everything. you even need energy to think!
2006-09-28 06:59:50 · answer #6 · answered by helenagilchrist@btinternet.com 1 · 0⤊ 0⤋
powering their electric tooth brushes.
making cars go
having a hot bath
walking to school
breathing
2006-09-26 01:45:15 · answer #7 · answered by helen g 3 · 0⤊ 0⤋
so we can get up off the couch to reach for the tv remote.
2006-09-25 06:17:19 · answer #8 · answered by candyfloss 5 · 0⤊ 0⤋
thats like asking "why do we need air" Think about what it would be like if we had no energy whatsoever! we would die !!!! YOU IDIOT !
2006-09-25 06:20:59 · answer #9 · answered by Sam D 2 · 0⤊ 1⤋
to live... to give them ump... power to be able to get through everydays life activities
2006-09-25 06:18:03 · answer #10 · answered by TMFULP. 3 · 0⤊ 0⤋