- #1
benrocks1
- 9
- 0
Can someone explain to me when you use 1/2mv^2-mgh as opposed to 1/2mv^2 or mgh
benrocks1 said:I know that 1/2mv^2 is Kinetic energy and mgh is potential energy. My question is in some example problems they use 1/2mv^2 and in others they use 1/2mv^2-mgh.
benrocks1 said:While the kinetic energy increases, the potential energy will decrease. Is that correct?
the_emi_guy said:Good, yes that is correct.
Conservation of energy means that the *total* energy remains the same (this is what conservation laws are, some quantity remains unchanged even though its constituent parts are changing).
So if the kinetic energy increase by some amount (say x), now much will the potential energy have to decrease?
What will happen to the quantity 1/2mv^2 - mgh is this case?
benrocks1 said:So 1/2mv^2-mgh would also increase by x?
benrocks1 said:the potential energy will decrease by x. does that mean that 1/2mv^2-mgh also decreases by x?
benrocks1 said:would 1/2mv^2-mgh remain the same?
benrocks1 said:I understand that mgh would = 0 when it hits the ground, but why is it 0 before the drop?
benrocks1 said:Oh so the kinetic energy is 0 because it is not in motion?
benrocks1 said:While the kinetic energy increases, the potential energy will decrease. Is that correct?
Kinetic energy is the energy an object possesses due to its motion, while potential energy is the energy an object possesses due to its position or state.
Kinetic energy should be used when an object is in motion or when there is a need for a source of energy to perform work.
Potential energy should be used when an object is at rest or when there is a need for stored energy to be converted into kinetic energy.
Yes, kinetic energy can be converted into potential energy and vice versa. For example, when a ball is thrown upwards, its kinetic energy decreases as it reaches the highest point of its trajectory, and its potential energy increases. When the ball falls back down, its potential energy decreases and its kinetic energy increases.
Kinetic energy can be calculated using the formula KE = 1/2 * m * v^2, where m is the mass of the object and v is the velocity. Potential energy can be calculated using the formula PE = m * g * h, where m is the mass of the object, g is the acceleration due to gravity, and h is the height or distance from a reference point.