Work, Energy, and Power
Work is the result of a force, acting over a certain distance. This distance This relationship between kinetic energy and work is called the work-energy theorem. refers to an activity involving a force and movement in the directon of the force. of energy and the application of the relationships for work and energy, so it is. Force If you're a taking classical physics, simply stated, a force is a push or a pull (So you can see there is an intimate relationship between work and energy).
A garage hoist steadily lifts a car up 2 meters in 15 seconds. Calculate the power delivered to the car.
Use kg for the mass of the car. First we need the work done, which requires the force necessary to lift the car against gravity: It has the same units as work, the Joule J.
There are many forms of energy: Work has been done on a spring to compress or stretch it; the spring has the ability to push or pull on another object and do work on it.Relationship Between Force and Potential Energy
The force required to stretch a spring is proportional to the distance it is stretched: A few of the problems in this set of problems will utilize this derived equation for power. Mechanical, Kinetic and Potential Energies There are two forms of mechanical energy - potential energy and kinetic energy.
Potential energy is the stored energy of position. In this set of problems, we will be most concerned with the stored energy due to the vertical position of an object within Earth's gravitational field.
Explain how force, energy and work are related? | Socratic
Kinetic energy is defined as the energy possessed by an object due to its motion. An object must be moving to possess kinetic energy. The amount of kinetic energy KE possessed by a moving object is dependent upon mass and speed.
The total mechanical energy possessed by an object is the sum of its kinetic and potential energies.
- Work, Power, and Energy
- Work, Energy, and Power
Work-Energy Connection There is a relationship between work and total mechanical energy. The final amount of total mechanical energy TMEf possessed by the system is equivalent to the initial amount of energy TMEi plus the work done by these non-conservative forces Wnc.
Work, Power, and Energy - Wikiversity
The mechanical energy possessed by a system is the sum of the kinetic energy and the potential energy. Positive work is done on a system when the force doing the work acts in the direction of the motion of the object. Negative work is done when the force doing the work opposes the motion of the object. When a positive value for work is substituted into the work-energy equation above, the final amount of energy will be greater than the initial amount of energy; the system is said to have gained mechanical energy.
When a negative value for work is substituted into the work-energy equation above, the final amount of energy will be less than the initial amount of energy; the system is said to have lost mechanical energy.
Explain how force, energy and work are related?
There are occasions in which the only forces doing work are conservative forces sometimes referred to as internal forces.
Typically, such conservative forces include gravitational forces, elastic or spring forces, electrical forces and magnetic forces. When the only forces doing work are conservative forces, then the Wnc term in the equation above is zero. For a spring this can be written: The larger k is, the stiffer the spring is and the harder the spring is to stretch.
If an object applies a force to a spring, the spring applies an equal and opposite force to the object. This is a restoring force, because when the spring is stretched, the force exerted by by the spring is opposite to the direction it is stretched. This accounts for the oscillating motion of a mass on a spring. If a mass hanging down from a spring is pulled down and let go, the spring exerts an upward force on the mass, moving it back to the equilibrium position, and then beyond.
This compresses the spring, so the spring exerts a downward force on the mass, stopping it, and then moving it back to the equilibrium and beyond, at which point the cycle repeats. This kind of motion is known as simple harmonic motion, which we'll come back to later in the course.
The potential energy stored in a spring is given by: In a perfect spring, no energy is lost; the energy is simply transferred back and forth between the kinetic energy of the mass on the spring and the potential energy of the spring gravitational PE might be involved, too. Conservation of energy We'll take all of the different kinds of energy we know about, and even all the other ones we don't, and relate them through one of the fundamental laws of the universe.
The law of conservation of energy states that energy can not be created or destroyed, it can merely be changed from one form of energy to another.
Mechanics: Work, Energy and Power
Energy often ends up as heat, which is thermal energy kinetic energy, really of atoms and molecules. Kinetic friction, for example, generally turns energy into heat, and although we associate kinetic friction with energy loss, it really is just a way of transforming kinetic energy into thermal energy. The law of conservation of energy applies always, everywhere, in any situation.