Why are work and energy different even though they have the same units?

In summary: So in summary, work and energy are two sides of the same coin, with work expressing the transmission or transformation of energy from one form to another. They have the same unit of measurement, with 1 Joule being equal to 1 Newton times meter. Additionally, work and energy have the same dimension and SI units, similar to how different types of force all have the same dimension and units. This highlights the interconnectedness and interdependence of these concepts in physics.
  • #1
PrakashPrasad
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Work unit is said to be Joule and Energy unit is also Joule. Work formulas in F x S ( Force x Displacement) .
We know
1 J = 1 F x `1 s
Now Energy is also measured in Joule(J)
So can we state :
E = 1 F x 1 s as 1 J = 1 F x 1 s
that is
E = W

Then why work and energy are different by definition and meaning
 
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  • #2
PrakashPrasad said:
We know
1 J = 1 F x `1 s

A small glitch, 1J = 1N x 1s.

PrakashPrasad said:
Then why work and energy are different by definition and meaning

What do you mean by that? A very "rough" statement back from high school times, is "Energy of a body, is the ability to do work". Now, what are the definitions you refer to?
 
  • #3
QuantumQuest said:
A small glitch, 1J = 1N x 1s.

I am not sure if you mean to correct a glitch or to present one. :)
The Joule is not Nxs (Newton times second).

The OP meant Force x distance when he/she wrote 1J= 1F x 1s (by s probably meaning distance, displacement).
 
  • #4
QuantumQuest said:
A small glitch, 1J = 1N x 1s.
What do you mean by that? A very "rough" statement back from high school times, is "Energy of a body, is the ability to do work". Now, what are the definitions you refer to?
Well is W = E ? I am not going by definition but rather its unit of measurement which in this case is Joule (for both Work & Energy)? So why we state that work is said to be done when a is force applied on a body and it displaces while energy is ability or capacity to do work - why are the unit of measurement same for both work / energy - JOULE?
 
  • #5
PrakashPrasad said:
Well is W = E ? I am not going by definition but rather its unit of measurement which in this case is Joule (for both Work & Energy)? So why we state that work is said to be done when a is force applied on a body and it displaces while energy is ability or capacity to do work - why are the unit of measurement same for both work / energy - JOULE?
Because work and energy is two sides of the same coin. If you lift a boulder (10kg) up 1m, it means that:
  • You have performed an amount of work = m⋅g⋅h = 10⋅9.81⋅1J = 98J
  • The boulder has gained an amount of potential energy = m⋅g⋅h = 10⋅9.81⋅1J = 98J
 
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  • #6
nasu said:
The Joule is not Nxs (Newton times second)

Yes, sorry for the typo, I meant N x m - of course, in SI units.

PrakashPrasad said:
Well is W = E ? I am not going by definition but rather its unit of measurement which in this case is Joule (for both Work & Energy)? So why we state that work is said to be done when a is force applied on a body and it displaces while energy is ability or capacity to do work - why are the unit of measurement same for both work / energy - JOULE?

Work expresses energy transmission or transformation of energy, from one form to another. So, they have the same unit of measurement.
As for the energy concept itself, I recommend this great insight by DaleSpam https://www.physicsforums.com/insights/what-is-energy/.
 
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  • #7
PrakashPrasad said:
Well is W = E ? I am not going by definition but rather its unit of measurement which in this case is Joule (for both Work & Energy)? So why we state that work is said to be done when a is force applied on a body and it displaces while energy is ability or capacity to do work - why are the unit of measurement same for both work / energy - JOULE?

Work is a form of energy
Potential energy is a form of energy
Kinetic energy is a form of energy

They ALL have the same dimension and SI units.

The similar way as

Electrostatic force is a form of force
Gravitational force is a form of force
Spring force is a form of force
Tension is a form of force
Frictional force is a form of force

They all have have the same dimension and SI units of N.

Zz.
 
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  • #8
QuantumQuest said:
Yes, sorry for the typo, I meant N x m - of course, in SI units.
Work expresses energy transmission or transformation of energy, from one form to another. So, they have the same unit of measurement.
As for the energy concept itself, I recommend this great insight by DaleSpam https://www.physicsforums.com/insights/what-is-energy/.
Work expresses energy transmission or transformation of energy - got it thanks
 
  • #9
ZapperZ said:
Work is a form of energy
Potential energy is a form of energy
Kinetic energy is a form of energy

They ALL have the same dimension and SI units.

The similar way as

Electrostatic force is a form of force
Gravitational force is a form of force
Spring force is a form of force
Tension is a form of force
Frictional force is a form of force

They all have have the same dimension and SI units of N.

Zz.
Thanks for the details
 

What is a Joule?

A Joule is a unit of measurement used to quantify energy. It is defined as the amount of work done when a force of one Newton is applied over a distance of one meter.

How is the Joule related to work?

Joule is the unit used to measure work, which is defined as the product of force and distance moved in the direction of the force. One Joule is equal to one Newton-meter (N*m) of work.

What is the relationship between Joule and energy?

Joule is the unit used to measure energy, which is the ability to do work. When work is done, energy is transferred or converted from one form to another. One Joule of energy is equal to one watt-second (W*s) or one kilogram-meter squared per second squared (kg*m^2/s^2).

How is Joule used in everyday life?

Joule is used in everyday life to quantify the amount of energy used or produced. For example, the energy output of a lightbulb can be measured in Joules, and the amount of energy consumed by a car is typically measured in Joules per kilometer (J/km).

What are some common misconceptions about Joule and energy?

One common misconception is that Joule is only used to measure electrical energy. In reality, Joule can be used to measure any form of energy, including mechanical, thermal, and chemical energy. Another misconception is that energy is created or destroyed. In reality, energy is conserved and can only be transferred or converted from one form to another, as stated by the law of conservation of energy.

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