WORK-AN INTRODUCTION : WORK-AN INTRODUCTION
Slide 2 : fisher men at work women at work mitzi brushing her teeth lady in kitchen See,they all are very busy.....
FORCE : FORCE It is the push or pull given to an object to move it to a distance.
so when we apply a force there’s a displacement
Slide 4 : ACTIVITY TIME....
Slide 5 :
WORK…. : WORK…. Work is said to be done when force displaces a body in direction of the force.
It is measured as the product of force and displacement in the direction of the force.
It’s a scalar quantity.
Physics concept of WORK : Physics concept of WORK WORK is done only when a constant force applied on an object, causes the object to move in the same direction as the force applied.
Factors on which work depends : Factors on which work depends Force
Displacement
Unit is joule W=Force*displacement
More Examples of WORK : More Examples of WORK You are helping to push your mother’s heavy shopping cart with a force of 50 N for 200 m. What is amount of work done? Work done, W = F x s
= 50 x 200
= 10,000 J
or
10 kJ (kilo-Joules)
Joule : Joule It is the work done when a force of 1n moves its point of application through 1m in its direction.
if work and displacement were in diff direction, what is the case?????? : if work and displacement were in diff direction, what is the case?????? W=f.d
=FdCos? F F d x Y ? FCos?
Positive and negative work…. : Positive and negative work…. Work done by the lady is positive, work done by force of gravity is negative…
POWER….. : POWER….. Work done/unit time
If W is the work done in t seconds
Power
Rate at which work is done
Unit is watt P=W/t
Power and velocity : Power and velocity power=work/time
work=force*displacement
power=(force*displacement)/time
=force*velocity
Thinking time…………. : Thinking time…………. A man pushes a roller with a force of 50N through a distance of 20m.calculate the work done if the handle of the roller is inclined at an angle of 60degree with the ground.(Cos60=1/2)?
F=50N
S=20m
W=FScos60
=50*20*0.5
=500j
THANK U………….. : THANK U…………..