Which amount of potential and kinetic energy changes but the total amount of mechanical energy stays the same?

Answer 1

Kinetic energy is the energy a body has because of its mass in motion.

and

Potential energy is the energy a body has because of its position in a gravitational field (- the energy trying to pull it down).

These are two different types of energy but the energy is interchangeable. For instance:-

If you hold a cube of steel 3 feet in the air, it's total energy is its gravitational potential (potential energy).

When you release the cube, this potential energy is converted into movement (kinetic energy).

When it hits the ground it will stop but the kinetic energy will have been dissipated in the form of other energies or mechanical work - sound, some heating of the ground and the object and perhaps a small dent.

Now the object is 3 ft closer to the center of the gravity field and has less potential energy than before (but still has some, it wants to fall further)

Thus the total energy equation is:-

Energy at the start (all potential) = Residual potential energy + kinetic energy of falling (which is = to dissipated energy -sound, heat and dent)

Answer 2

For particle motion, there are two types of energy (that I am aware of): kinetic and potential. Kinetic energy is the energy of movement, or the type of energy that particles have when actually in motion. Potential energy is the capacity for a mass to do work, usually based on its position in space. For example, picture a large boulder on top of a hill. In terms of kinetic energy, its energy level is nil, but it has a large amount of potential energy because, if given a small push, it will roll down the hill. The energy level of the system will remain the same, except now all the potential energy will transfer to kinetic energy as the boulder rolls. Eventually, all that kinetic energy will get transfered into the surrounding system through friction, but the energy in the entire system will remain the same.

Answer 3

In a system like a pendulum the kinetic plus potential energy stays the same, but when the pendulum goes through its lowest point all the energy is kinetic, while when it is stopped at the end of its swing, all the energy is potential. With a practical pendulum the total energy runs down slowly over time.

Answer 4

Nothing!

When there are no energy losses through friction, the sum of the PE and the KE is constant. An example is seen in a planet's orbit around the Sun. The planet's distance varies as it follows its elliptical orbit, and the speed also varies as the distance changes, but the total energy stays the same.

When there are frictional losses, the total energy decays slowly to heat. An example is a pendulum that is swinging freely. The KE and PE are exchanged twice per cycle, but as the total energy decays away the pendulum slowly comes to rest over a long period of time.

Answer 5

In an ideal situation, there's the conservation of mechanical energy, so the total mechanical energy remains constant even though the potential and kinetic energy change. This is exemplified in situations where objects experience changes in height or speed, like a swinging pendulum or a roller coaster ride.

Answer 6

kinetic energy is movement energy

potential energy is energy that could be turned into energy

Answer 7

mechanical energy is when something that moved stopped moving but can still move and potential energy is when something can (is ready to move) and kinectic energy is when something is moving

Answer 8

It stays as potential energy until transformed into kinetic energy.