From the expression E = mgh for potential energy, how can I express the unit of energy, the joule, in terms of kilograms, metres and seconds? could anyone explain to me what this question is asking me for cuz I don't understand it, to be honest? thanks
E=mgh=kg*m/s^2*m= kg*m^2/s^2= joule
so the joule is a "derived" unit, that is, it is not a fundamental unit.
thank you bobpursley
Sure, I can help explain what the question is asking.
The question is asking you to express the unit of energy, which is the joule, in terms of kilograms, meters, and seconds. In other words, it wants you to find a way to represent the joule using these three basic units.
To do this, let's look at the expression for potential energy, E = mgh, where:
- E represents the potential energy,
- m represents the mass of the object,
- g represents the acceleration due to gravity,
- h represents the height of the object.
The unit of potential energy, as given in the question, is the joule. The joule (J) is the standard unit of energy in the International System of Units (SI).
To express the unit of potential energy, the joule, in terms of the base units (kilograms, meters, and seconds), we need to break down the expression E = mgh.
The unit of mass is kilogram (kg). The unit of acceleration due to gravity is meters per second squared (m/s^2). The unit of height is meters (m).
To express the unit of energy, the joule (J), in terms of these units, we need to substitute the respective units into the expression.
So, substituting the units into the expression E = mgh, we get:
Joule (J) = kilogram (kg) x meters per second squared (m/s^2) x meters (m)
Simplifying the expression, we have:
Joule (J) = kilogram meter squared per second squared (kg m^2/s^2)
Therefore, the unit of energy, the joule, can be expressed in terms of kilograms, meters, and seconds as kilogram meter squared per second squared (kg m^2/s^2).
I hope this explanation helps! Let me know if you have any further questions.