Physics, asked by ShreshthWadhwa001, 11 months ago

work energy theorm applications

Answers

Answered by Saifßàã
2
HLO FRIEND:-)

Introduction

According to this theorem the net work done on a body is equal to change in kinetic energy of the body. This is known as Work Energy Theorem. It can be represented as

Kf – Ki = W

Where, Kf = Final kinetic energy

Ki = Initial kinetic energy

W = net work done

So the above equation follows law of conservation of energy according to which we can only transfer energy from one form to another. Also here the work done is the work done by all forces acting on the body like gravity, friction, external force etc.

According to Work energy theorem,

Work done by all the forces = Change in Kinetic Energy

Wg + WN + Wf  =Kf – Ki

Where, Wg = work done by gravity

WN = work done by normal force

Wf = work done by friction

Kf = final kinetic energy

Ki = initial kinetic energy

Work done by a constant force

A constant force will produce constant acceleration. Let the acceleration be ‘a’.

From equation of motion,

v2 = u2 + 2as

2as = v2 – u2

Multiplying both side with mass ‘m’

(ma).s = (mv2–mu2)2

F.s = (mv2–mu2)2

Comparing the above equation we get,

Work done by force (F) = F.s

Where ‘s’ is the displacement of the body.

Work done by Non-Uniform Force

Now the equation,

W = F.ds

This is only valid when force remains constant throughout the displacement.

For these kinds of forces, we can assume that force remains constant for a very small displacement and then integrate that from initial position to final position.

W = ∫xfxiF(x)dx

This is work done by a variable force. A graphical approach to this would be finding the area between F(x) and x from xi  to xf .

HOPE ITS HELP U_^_^
Similar questions