FORCE AND ENERGY

FORCE AND ENERGY

WORK AND ENERGY

Ø WORK:

Work is done whenever a force makes something move towards its direction. The greater the force and the greater the distance moved, the more work is done.

The SI unit of work is (J) joule.

-Worked Equation-

WORK DONE = FORCE * DISTANCE MOVED IN THE DIRECTION OF FORCE.

· DEFINATION OF UNIT JOULE:

1 Joule of work is done when a force of 1N moves an object 1m in the direction of the force.

Ø ENERGY:

Things have energy they can be used to do work; like work, energy can be measured in joules.

The law of conservation of energy to gather with the idea of energy existing in different forms make an area of physics that is the most powerful and the most misunderstood of all. Essentially the concept of energy helps us to understand and explain the way the universe behaves-just like any other law of theory of physics.

Ø FORMS OF ENERGY:

When describing different forms of energy, the following names are sometimes used –

§ Kinetic Energy- This is energy due to motion. All moving objects have kinetic energy.

§ Potential Energy- This is energy which an object has because of its position, shape or state. There are several different types of potential energy. Here are some terms used to describe them:

Gravitational Potential Energy- A stone held up in the air can do work when dropped because gravity will pull it down words. The stone has gravitational potential energy.

Elastic potential energy- A stretched rubber band can do work when released, so can a compressed spring. Both have elastic potential energy.

Chemical potential Energy- When a fuel burns, its energy is released by chemical reactions. The energy stored in the fuel is called chemical potential energy or chemical energy for short. Batteries also store it. So do foods. Without it, your muscle could not move.

Electrical Potential Energy- In circuits, the current is a flow of tiny charged particles called electrons. These come from atoms. Electrons can transfer energy from, for example, a battery to a light bulb. They have electrical potential energy, or electrical energy for short.

Nuclear Potential Energy- an atom has a nuclear at its centre. This is made up of particles, held there by strong forces. In some atoms, the particles become rearranged, or the nucleus splits and energy is released. This is called nuclear potential energy or nuclear for short.

The following terms are sometimes used when describing energy which is being transferred from one place to another or form object to another:

Thermal Energy- When hot objects cool down, their atoms and molecules slowdown and lose energy. This is known as thermal energy. Engines use thermal energy to do work. For example in a car engine, burning fuel produces hot gases which expand push on pistons and make them move. The motion is used to turn the wheel of a car.

Radiated Energy- The sun radiates lights. Loudspeakers radiate sound. Light and sound both travel in the form of waves. These carry energy.