# Why energy rate did not replace power = Force times velocity?

After reading the history of horse power (and power), the physical definitions for them and after testing the theory in rally races, I'm curious what were the reasons for selecting this word (power) as a "badge" for $$\mathbf F\cdot \mathbf v$$ later called energy rate.

According to https://hsm.stackexchange.com/a/3255/19097 the power might be "ability to act or do." I ask because energy rate is more transparent than "power" if we take into consideration their meanings.

https://en.m.wikipedia.org/wiki/Horsepower

Why wasn't joule/second enough? Why the need for a new unit (watt)? The energy concept is younger than power. Speed is also a rate: m/s or km/h or rpm and so on. Speed does not have an analog in terms of measuring unit.

Example: The car travels at a speed of 10 Names (Name Surname of the guy who never defined this so far).

Found this interesting question that relates to power Etymology of "power" (math.). And this When was the concept of “Power” defined?. So according to https://hsm.stackexchange.com/a/13309/19097, Watt was not aware of energy and he thought that power is force multiplied by velocity.

Also if energy is younger 1840 than power 1770, why didn't joule/second replace the watt? https://hsm.stackexchange.com/a/2554/19097

• Question should not look like revision histories, see meta.stackexchange.com/questions/323116/… Oct 5, 2023 at 14:05
• @Mauricio Thank you for your help. It feels like you need a colledge to know all the rules for asking a question. Oct 5, 2023 at 16:54

The equality $$dE/dt=vF$$ can be considered a nontrivial insight, and not simply a definition of the term on the right (ot left). An analogous question would be: in light of the equality $$E=mc^2$$, why do we need the concept of energy since we already know mass and speed of light?
Or maybe I misunderstand the question. There seem to be several ones. One seems to be: why did people call $$dE/dt$$ the power and not just energy rate. There is probably an interesting history to this, but similarly you could ask why people called $$dp/dt$$ the force and not simply the momentum rate.