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Sunday, January 27, 2013


Physics:
Formula and Example of Force


The Formula Of Counting Work Is:

Work= force  x displacement 

               W= F s
Where:

 F = Force, unit of measurement is N (Newtons)

S = Displacement, unit of measurement is M (Meters)

W = Work, unit of measurement is J (Joules)


Examples:


Mother pushing baby stroller
1. What is the work needed to push a 50 N load, if the load moves 20 meters in the same direction of force?

Answer:  F = 50m      F x D=
               D = 20m      50 x 20 = 1000J


2. What is the work needed if a person shoots the ball and flew over 4 meters high, if your body has a 60 kg mass?
A girl shooting a basketball



Answer:   F = M x G
                F = 60 x 10
                F = 600
                F = 600 x 4 = 2400J

 *It is times 10 because their is gravity acting upon it 

-------------------------------------------------------




 Work = Force x Distance 
           = ( 70 + 20 - 20) x 2
           = 80 x 2 = 160 
                           


                               





Work = Force x Distance 
          = 70 x 2
          =  140 

Wednesday, January 16, 2013

WORK



Physics: work

     In Physics Class we are studying a new topic about work and energy. In physics, work is defined as something which relates to force and displacement of an object. So, in physics, work means a force that causes a displacement of an object. So, if a force does not displace and object, then it is not considered as work.
         

  In class we also tried to define either it is work or not. There are many kinds of work, for example lifting a box, pushing or pulling a chair, throwing a trash, throwing a ball, and many other kinds. These examples are considered as work because there is force that makes the object moves. There are also different kinds of example that is not an example of work, like a person is pushing the wall, a child produces force to keep the chair in her hand, play tug of war in the losers team, and many more. In physics, these kinds of examples are considered as not doing work. Although they produce muscular force, the object is not moving anywhere. So, a force that causes n displacement is considered as not doing any work or the work is equal to zero.

There are 2 statements about work. They are:



  •  If a force does not cause any displacement, then the work is zero
  •  If a force does not have the same direction as the displacement, then the work is zero.


This picture is not an example of work, because
the object is not moving anywhere.


This picture is an example of  work, because there is
force that makes the object moves.