is Joule, newton and one watt

[Pelu]

sup all... i dont understand this well.. but is one joule the same as one newton and one watt????

I dont really understand what is a joule about lol..

 

[Born2bwire]

A joule is a newton-meter. A watt is a joule per second. Joule measures work. So a joule is the amount of work done when applying a force of 1 newton over the distance of a meter. Watt is a measure of power, it is the equivalent of one joule of work per second, that is the rate of work expended.

 

[Pelu]

all this things are almost the same... so confusing...

I was reading that wikipedia but it got a full confuse ray in my mind lol...

 

[Pelu]

the real deal is waht joules have to do with volts lol... i see a lot of joules over here and there in the side of volts but the info i got is joule newtons and watts lol...

 

[Born2bwire]

Originally posted by: Pelu
the real deal is waht joules have to do with volts lol... i see a lot of joules over here and there in the side of volts but the info i got is joule newtons and watts lol...

Electrical power, using simple circuit analysis, is current*voltage. So a watt is one amp-volt, or a joule is one amp-volt-second. That is, given a circuit that draws one amp of current out of a source that is providing a potential difference of one volt, then the amount of energy expended by the source in one second is one joule.

EDIT: To clarify:

Newton = Force = Acceleration of an object (more specifically the change in momentum which can also involve the change in mass of a moving object)
Joule = Energy/Work = Application of force over distance.
Watt = Power = The rate at which energy/work is created/done.

 

[silverpig]

You have a big 'ol fat lady who needs help up the stairs. Because she's so heavy, it'll take a lot of force to move her. How tired you will be after getting her up the stairs will depend on how many stairs you have to climb while exerting this force and tells you how much work you have to do to get her there. If you're He-Man, it'll take you very little time to winch her up the stairs because "You have the power!"

Newtons measure how strong you are.
Joules measure how much work you have to do.
Watts tell you how quickly you can get the work done.

A lot of people mix up force (newtons) and power (watts).

 

[templar165]

BY definition,

Newton is the amount of force applied
Joule is amount of energy spent/gained while applying the force; and
Watt is your power, i.e., if you kept on applying this force, how much energy would you lose/gain in a particular interval of time?

 

[imported_ssj4Gogeta]

Originally posted by: Born2bwire
EDIT: To clarify:

Newton = Force = Acceleration of an object (more specifically the change in momentum which can also involve the change in mass of a moving object)
Joule = Energy/Work = Application of force over distance.
Watt = Power = The rate at which energy/work is created/done.

Force isn't exactly acceleration or change in momentum, it's the RATE of change in momentum. Or, force*time = total change in momentum.

 

[jagec]

Originally posted by: silverpig
You have a big 'ol fat lady who needs help up the stairs. Because she's so heavy, it'll take a lot of force to move her. How tired you will be after getting her up the stairs will depend on how many stairs you have to climb while exerting this force and tells you how much work you have to do to get her there. If you're He-Man, it'll take you very little time to winch her up the stairs because "You have the power!"

Newtons measure how strong you are.
Joules measure how much work you have to do.
Watts tell you how quickly you can get the work done.

A lot of people mix up force (newtons) and power (watts).

Hehe, nice.

 

[PlasmaBomb]

Originally posted by: silverpig
You have a big 'ol fat lady who needs help up the stairs. Because she's so heavy, it'll take a lot of force to move her. How tired you will be after getting her up the stairs will depend on how many stairs you have to climb while exerting this force and tells you how much work you have to do to get her there. If you're He-Man, it'll take you very little time to winch her up the stairs because "You have the power!"

Newtons measure how strong you are.
Joules measure how much work you have to do.
Watts tell you how quickly you can get the work done.

A lot of people mix up force (newtons) and power (watts).

I concur. Nice :thumbsup:

 

[KIAman]

You've got a Bugatti Veyron and you want to go on a joyride.
This car is a beast! Some stats...

Engine Horsepower: 1001HP - Translation: 746,000 Watts
Engine Torque: 920 lb/ft - Translation: 1,247.4 Joules

You get in the car, check for police, and hit the throttle as hard as you can.

The car lurches a little while all 4 tires attempt to bite the pavement.

You go 0-100 in 5.5 seconds and feel 1.12g of acceleration - Translation: 1,575 Newtons... assuming you are 300lbs

The car also feels 1.12g of acceleration - Translation: 21,848 Newtons

Oh no! The police clocks you going 249 mph! You are going to serve 20 years in jail for going 184 mph over the speed limit, all for a 50 second joyride!

 

[imported_ssj4Gogeta]

Also, I'd like to point out that Torque is the rotational equivalent of Force, although it's unit is of work (Joules). Angular displacement is dimensionless, so when you multiply torque with angular displacement, you get work. Torque isn't work.

 

[OCedHrt]

Originally posted by: silverpig
You have a big 'ol fat lady who needs help up the stairs. Because she's so heavy, it'll take a lot of force to move her. How tired you will be after getting her up the stairs will depend on how many stairs you have to climb while exerting this force and tells you how much work you have to do to get her there. If you're He-Man, it'll take you very little time to winch her up the stairs because "You have the power!"

Newtons measure how strong you are.
Joules measure how much work you have to do.
Watts tell you how quickly you can get the work done.

A lot of people mix up force (newtons) and power (watts).

I wish I could give you something for this awesome explanation

 

[polarbear6]

ahh here in my country a 13 year old can answer that
joule is for energy newton is for force watt is for power farads is for capictance and so on and so forth
power = energy / time(for which energy was applied) = force * distance / time(distance that the body moved because of the force)
force is a vector k
energy a scalar ,power i dont remember
consider this example
a bucket of water to move it u need force (newton)
to move it by 10 mts up in the air u will need force when u r done that water gets energy(joules)
the time taken by u to move that water annd the energy constitute ur power

 

[imported_ssj4Gogeta]

Originally posted by: ganesh1
ahh here in my country a 13 year old can answer that

An 11 year old, actually. That's when I learned the meaning of these terms. And yes, I'm from India.

Power, being dW/dt is a scalar, since work is a scalar.

 

[polarbear6]

Originally posted by: ssj4Gogeta

Originally posted by: ganesh1
ahh here in my country a 13 year old can answer that

An 11 year old, actually. That's when I learned the meaning of these terms. And yes, I'm from India.

Power, being dW/dt is a scalar, since work is a scalar.

cool well some guys here in india are giving iit foundations to even 6th class children
so they will also know the meaning of that
so i guess 11~ 13 year old can answer that

yeah power is a scalar was unsure of that but hey
multipication of a scalar with a number gives a scalar

how old r u ??
i live in hyderabad where do u live

 

[imported_ssj4Gogeta]

18, from Lucknow. Preparing for iit jee.

how old are you?

 

[polarbear6]

Originally posted by: ssj4Gogeta
18, from Lucknow. Preparing for iit jee.

how old are you?

17 am also preparing iit jee
damn iam really having issues with integral calculus and optics(i have not attended those at my classes)
most probably if i dont get selected i will drop off a year
hey are you writing repeat
cause iam 17 and this is my first attempt
so u must be writing a repeat huh ??

this is my yahoo id drop me a im sometime
iitadity007@yahoo.co.in

edit: actually there is no such thing as writing a repeat, my bad
i mean to say are you giving iit another shot ?

 

[imported_ssj4Gogeta]

We'd better not talk about it here. We've already hijacked the thread. lol I'll pm you or im you.

 

[Inspector Jihad]

Originally posted by: ganesh1
ahh here in my country a 13 year old can answer that

way to be a douchebag. :thumbsup:

also, to seem less like a dick, use you and are, instead of u and r.

 

[gseattle]

High school physics teacher holding a weight on his outstretched hand said he's doing no "work".
He was expending energy against gravity though.

Since then I've been in a funk, just figuring the word work in physics might be a misnomer.
I can see that a paperweight on a table is doing no work ...
... and I suppose this is in the neighborhood of a magnet-on-a-steel-ceiling endless-energy debate thought-recreation...
... and/or a person holding an object is not the same as a paperweight on a table burning no calories ...
... but ...

How can energy be expended with no "work" done?

????

 

[IronWing]

The weight lifter is doing no work on the bar when the bar is at the top of his lift and is not moving. The weight lifter is expending energy on biochemical processes to keep his muscles tensed. The "work" done is creating chemical reaction products, moving blood, moving air, generating waste heat, and, if he is grunting, sound waves.

 

[serpretetsky]

You've got a Bugatti Veyron and you want to go on a joyride.
This car is a beast! Some stats...

Engine Horsepower: 1001HP - Translation: 746,000 Watts
Engine Torque: 920 lb/ft - Translation: 1,247.4 Joules

Thread necro! (im ok with it )

Just because torque has the same units as Energy does not mean you measure it is a measurement of energy. You do not measure torque in joules.

Counter example: You can have a passive spring motor provide torque forever if its jammed stuck. There is 0 joules/energy being transferred. And although there is potential energy stored in the spring, this value will not necessarily be equal to the torque.

Engine torque is not measured in joules. It is measured in lb*ft or N*m.

 

[serpretetsky]

High school physics teacher holding a weight on his outstretched hand said he's doing no "work".
He was expending energy against gravity though.

Physics is often very theoretical (its a good thing, we must understand fundamentals first!).

Human body is a poor study for this. Another poor study example is a helicopter. It just sits hovering, not changing altitude, naive physics would tell you that it uses no energy hovering there. Please tell the helicopter pilot that he doesn't need any fuel to hover.

There are lots of examples of mechanisms that require energy just to be in a static position, but if if you don't factor these complex mechanisms into the equations, the equations will just give you a lower bound of how much energy is needed to do something. Helicopter blades that need to actively be driven to provide a constant supply of air mass to counteract gravity, or human muscles that require a supply of energy to stay flexed, all add components to the equations that make the equations more complex. If you don't include these extra complex components, you will just get lower bounds.

Sometimes lower bounds is enough for engineer to ballpark something. Sometimes its not.

It doesn't require any energy to hold up a weight. Just put it on a pedestal and marvel at how inefficient your muscles are for holding things in static positions. But it DOES require energy to lift a weight against gravity. There is no classical newtonian machine that you could EVER build that will be able to lift an object without requiring some sort of energy input.

But then you might ask for the static case: "Where is all of that energy that i'm putting in going, if not holding up the object". Usually this answer is heat. Flexing a muscle without moving anything ultimately just produces heat. Helicopter hovering produces some kinetic energy in the flow of air moving down, and a lot of heat. Also, a lot of that kinetic energy ultimately transforms to heat later anyways.