Hi! This question isn't necessarily checking work, but more of some help figuring something out. In science, we are learning everything about energy. I am currently on a test, but I can't figure out how to calculate potential and kinetic energy. They gave me numbers, and I know that my answer will be in J's. Can anyone tell me how to calculate energy? thank you! :-)
K.E. = 1/2*m*v^2
P. E. = mgh
Oh my.
Well, there are three sorts that you may be working on:
1. Potential energy
This includes gravitational potential energy, usually simplified as m g h close to the surface of earth where m is mass in kilograms and g is gravitational acceleration, about 9.81 m/s^2 on earth surface. h is height difference in meters up from whatever you define as zero energy height. As you said, meters, seconds, kilograms yields Joules. You may also see the universal formula force = G M1 M2 / d^2 between any two objects a distance d apart and with masses M1 and M2. Google that law of gravitation.
Potential energy also is in a spring when you compress it or stretch it. That is in general (1/2) k x^2 where k is the "spring constant" and x is the distance from un- stretched length.
There are many other forms but I think these are the two you are most likely to see until you get to electricity etc.
2. Kinetic energy
You will probably see this as (1/2) m v^2 where v is the speed of the masd m. With circular motion this is expressed usually as (1/2) I omega^2
where I is the"moment of inertia " and omega is the angular velocity. This is really the same old (1/2) m v^2 but put in a form that is easily used for rotating objects.
3. Heat energy
You are likely to see this as just lost Joules due to friction or whatever.
In a perfect system the total kinetic and potential energy, for example (1/2) m v^2 + m g h is constant. However if there is friction then something heats up and mechanical energy is lost to heat energy.
That is very simplified but what I have a hunch you need immediately.
Hi! I'd be happy to help you understand how to calculate potential and kinetic energy.
Potential Energy:
The formula to calculate potential energy is PE = mgh, where PE is the potential energy, m is the mass of the object, g is the acceleration due to gravity (usually taken as 9.8 m/s^2 on Earth), and h is the height or elevation from a reference point (usually the ground).
To calculate potential energy, you will need to know the mass of the object and its height above the reference point. Multiply the mass (in kilograms) by the acceleration due to gravity (in meters per second squared) and then multiply that result by the height (in meters). The unit of potential energy is joules (J).
Kinetic Energy:
The formula to calculate kinetic energy is KE = 0.5mv^2, where KE is the kinetic energy, m is the mass of the object, and v is the velocity (speed) of the object.
To calculate kinetic energy, you will need to know the mass of the object and its velocity (speed). Multiply the square of the velocity (in meters per second) by half of the mass (in kilograms). The unit of kinetic energy is also joules (J).
Remember to use consistent units in your calculations. For example, if the mass is given in grams, convert it to kilograms before using it in the formulas.
I hope this explanation helps you understand how to calculate potential and kinetic energy! If you have any further questions, feel free to ask. Good luck with your test!