WORK ,ENERGY & Types of WORK AND ENERGY

In this article, I will be describing about Work & Energy. For understanding these terms, we need to know about the following terms work, +ve work , -ve work , zero work and energy , type of energy ( kinetic energy, potential energy, mechanical energy).
Now, Start with work.

WORK- when a force applied on a body and force displaces the body through a certain distance in the direction of force then work is said to be done.

                    W = F.S

                    W = (F cos💊)S
     
                    W = F S cos💊

(where  F= force, S= displacement are the Vector quantities)

(where Fcos💊  is the component of force along the direction of displacement.)

unit of work - J  or N-m
work is a SCALAR quantity

               *************************

TYPES OF WORK

1. POSITIVE WORK
2. NEGATIVE WORK
3. ZERO WORK

POSITIVE WORK
It means that force or the component of force is parallel to the displacement.

Mathematically, Work is said to be +ve , if value of angle theta  between the directions of F & s is either zero or an acute angle.

NEGATIVE WORK

It means that force or the component of force is opposite (or anti-parallel) to displacement.

Mathematically, work is said to be -ve , if value of angle theta between the directions of F & s is either 180° or an obtuse angle.

ZERO WORK

Work done can be zero, if

♦ No force is being applied on a body.

          W = F . s  ➡ Fs cos (theta)

        •.• F = 0 ,     .°.  W = 0

♦ Although the force is being applied on a body but is unable to cause any displacement in the body.

W = F . s  ➡ Fs cos (theta)

•.• F is  not equal 0 but s=0 ,     .°.  W = 0

♦ Both F & s are finite but angle theta between the directions of force and displacement is 90°.

In such a case

W = F . s  ➡ Fs cos (theta) ➡ Fs cos 90°

Share on Google Plus

About Unknown

This is a short description in the author block about the author. You edit it by entering text in the "Biographical Info" field in the user admin panel.