power, work and energy (kinetic and potential)

 

What is Work, Energy and Power?
Work
Definition	The work done by a force is defined to be the product of component of the force in the direction of the displacement and the magnitude of this displacement.
Formula	Work can be calculated by multiplying Force and Distance in the direction of force as follows W = F × d
Unit	The SI unit of work is the Joule (J)
Energy
Definition	Energy is defined as the capacity to do work.
Formula	The energy stored in an object due to its position and height is known as potential energy and is given by the formula: P.E. = mgh
Unit	The SI unit of energy is Joules (J).
Power
Definition	Power is defined as the rate at which work is done.
Formula	The formula for power is P = W/t
Unit	The SI unit of power is Watt (W).

(1) Work:

Work is said to be done when a force produces a displacement in the body and acts in any direction except perpendicular to the direction of displacement.

Work = Force × Displacement

SI unit of work is ‘joules’.

(2) Energy:

Capacity to do work is called energy. For example, an 18-year old man has more capacity to do work (like lifting a table) than a 6-year old child. SI unit of energy is ‘joules’.

(3) Power:

Power is the rate of doing work or the rate of transfer of energy. If W is the amount of work done in time t, then power is given by the expression,

It is expressed in watt (W).

(4) Kinetic energy:

Kinetic energy is the energy possessed by a body by the virtue of its motion. A body uses kinetic energy to do work. Its SI unit is ‘joules’.

Expression for kinetic energy,

    

Kinetic energy of hammer is used in driving a nail into a log of wood. Kinetic energy of air is also used to run wind mills.

(5) Potential energy:

Energy of a body possessed by virtue of its configuration or position is called potential energy. Its SI unit is ‘joules’.

Expression for gravitational potential energy,

  

U=mgh

Where, m = mass of the object

g = acceleration due to gravity

h = height of the object from reference line

Power dissipation is the process of converting electrical energy into heat in a resistor. It can be calculated using the following formulas:

P = V x I: Where P is power in watts, V is voltage in volts, and I is current in amperes

P = I²R: Where R is the resistance in ohms 

Power dissipation can cause a resistor to heat up, which can affect its performance and lifespan. To avoid damage, it's important to choose a resistor with a power rating that's higher than the expected power dissipation. 

What is Power?

The capacity to do work is termed Energy. The Energy expended to do work in unit time is termed as Power. It is represented as P.

Power Formula is articulated as,

 

 

 

 

or,

Where,

The Energy Consumed to do work = E

Work done = W 

Time taken= t 

In any electrical circuit, the power is computed making use of these three formulas

In regard to Voltage and current, it is articulated as

P = V×I

In regard to current and resistance, it is articulated as

P = I^2R

In regard to voltage and resistance, it is articulated as

 

 

Where,

A voltage applied across the two ends =V,

Current flowing in the circuit = I and

Resistance = R.

The Power Formula is used to compute the Power, Resistance, Voltage or current in an electrical circuit. The standard metric unit of power is the Watt.