PRACTICAL SCIENCE EDUCATION II BODIES STYLE IN THE STATIC CASE

PRACTICAL SCIENCE EDUCATION II BODIES STYLE IN THE STATIC CASE

GROUP:

1. ERDITYA EKANOVIE N. (09312244002)
2. ARFINDA RISKI K. (09312244008)
3. MUHAMMAD IZZATUL F. (09312244025)
4. RENI WITULASARI S. (09312244041)
5. SISKA PRATAMA (09312244031)

FACULTY OF MATHEMATICS AND SCIENCE
YOGYAKARTA STATE UNIVERSITY
2011




I. GOAL
1. To describe the third class of lever system in arm muscle force.
2. To calculate muscle force is working.
II. BASIC THEORY
In physics, a lever is a rigid object that is used with an appropriate fulcrum or pivot point to either multiply the mechanical force (effort) that can be applied to another object or resistance force (load), or multiply the distance and speed at which the opposite end of the rigid object travels.
(http://en.m.wikipedia.org/wiki/lever)
Lever system in the body divide into three, there are first lever system, second lever system, and third lever system.
In a class I lever system (also known as a first class lever system). The fulcrum is located between the force and the resistance. An example of this type of a lever system is a child’s see saw. The children alternate between being the resistance (weight) and the force across a fulcrum in the center of the seesaw board. An example of a first class lever system in the body is the head and neck. The joint in the neck is the fulcrum , the posterior neck muscles generate the forces that pulls down the back of the head, and raises the face.
In a class II (also known as a second class lever system), the resistance is located between the fulcrum and the force. An example is a wheelbarrow where the wheel is the fulcrum and the person lifting on the handles provides the force. The load, or resistance, carried in the wheelbarrow is placed between the wheel and the operator. in the body, an example of a class II lever system is the foot and ankle when a person stands on his toes. The calf muscles acts as force generators and pull the heel (end of the lever) to elevate the foot and the weight of the entire body, with the ball of the foot acting as the fulcrum.
In a class III (also known as a third class lever system) is the most common type of lever system in the body. In this system, the force is located between the fulcrum and the resistance. An example is a person operating the shovel. The hand placed on the handle closest to the blade acts as the force to lift the resistance, such as a shovel full of dirt and the hand placed near the end of the handle act as the fulcrum.
(http://answer.yahoo.com/question/index?qid=2008060315202AAYdiJW)
III. Tools and Materials
1.Ruler
2.Barbell (in varies of mass)
3.Bow
IV.Procedure








1.Lift the the barble that was known it mass
2.Calculate the lenght of forearm (AB in the picture)
3.Define the distance of point of support and muscle force (the lenght of power arm)= 4 cm
4.Define point of center of gravitation (Cg) is a half of the lenght of forearm
5.Write the result of measurement in the table.
6.Calculate the force of muscle withe equation
7.Repeat the experiment with the second and third person that have different lenght of forearm
8.Repeat the experiment with different weight of barble
9.Repeat the experiment with forearm shapes definite angle
10.Calculate muscle force (M) with the equation
11.Conclude how the related between the value of angle and the value of muscle force
VII. DISCUSSION
At this attempt with aim to describe the third class of lever system in arm muscle force dan calculate muscle force is working, tools and materials which applied in the form of Ruler, Barbell (in varies of mass) and Bow. people doing this attempt is Siska pratama and Erditya ekanovie nindithasari..
Style at body basically there is two type that is Style at body in situation of static and force at body in dynamical state. Body internal force in the situation static is when body in balance situation, the amount of moment of forces and styles equal to nulls. Muscle and bone system function as lever. There is 3 lever system class: what one of them is third class lever system.
In a class III lever system also known as a third class lever system, is the most common type of lever system in the body. The force is located between the fulcrum and the resistance. In the body, an example of a class III lever system is the action of the biceps muscle or force generator pulling on the forearm or lever to flex the elbow or fulcrum and elevate the hand (resistance).
This attempt related at picture under this to determine large from muscle force

With description A as the point of spot, M as muscle force, Cg as center of gravity and the last W as weight.
The first step which we do is lift the the barble that was known it mass, here applied by barbell with mass of 1 kg and 2 kilogram which in modeling by Siska and Erditya in change. Like seen at picture under this;


The second is Calculate the length of forearm where siska have length of 32,5 cm and erditya have length of 29 cm available for seen by is picture under this;



Third step is define the distance of point of support and muscle force as according to guide hence the length of power arm have large equal to 4 cm.. hereinafter is define point of center of gravitation ( Cg) is a half of the length of forearm. Center of gravitation got by dividing two the length of forearm or (AB/2) causing got by result everyone of siska and erditya each is 16,25 cm and 14,5 cm.
Then, Calculate the force of muscle with equation (W/M) = (AM/AB).at the angel 00 with barbell weight of 1 kilogram got by muscle force from siska is 81,25 N. After that we are repeat the experiment with the second person that have different lenght of forearm. Here done by erditya and yielded by large muscle force 72,5 N. Heavily barbell which applied hereinafter is equal to 2 kg. Where got by is style everyone of siska and erditya equal to 162,5 N and 142 N.

The experiment then doing with forearm shapes definite angle ( ) like the picture above and got as follows; with angle and barbell weight of 1 kg muscle force yielded by siska and erditya each is 70,36 N and 62,79 N while barbell weight of 2 kilogram got by muscle force equal to 140, 72 N and 125,58 N. With angle and barbell weight of 1 kg muscle force yielded by siska and erditya each is 40,625 N and 36,25 N while barbell weight of 2 kilogram in getting muscle force equal to 81,25 N and 72,5 N.
At the done attempt, big from muscle force which yielded base on three factor that is the length of forearm, the mass of barbell ( weight) and the angle. Relation between the third is ever greater of barbell mass in this case weight. and ever greater the length of forearm hence would be ever greater also muscle force. while is ever greater angle of hence style which result progressively kecil.Ini is provable x self by both person If barbell weight which at first one kilogram was made two kilogram hence both person flavor will be heavier.

Siska feel heavier than at erditya same barbell weighing because having the length of forearm is longer. On the other hand, both lighter flavor when the corner preponderated by large from 00 .
VIII. CONCLUTION
Class III lever system is the action of the biceps muscle or force generator pulling on the forearm or lever to flex the elbow or fulcrum and elevate the hand (resistance)
The muscle force with barbell have a weight of 1 kg and angle 00 300 ,600 as well as AM 4cm from siska each 81.25 N, 70,36 N, 40,625 N. while from erditya each 72.5 N, 62.79 N, 36,25 N.
The muscle force with barbell have a weight of 2 kg and angle 00 300 ,600 as well as AM 4cm from siska each I62.5 N, 140.72 N, 81.25 N while from erditya each 142 N, 125.58 N, 72.5 N.
IX. REFFERENCE
http://en.m.wikipedia.org/wiki/lever
http://answer.yahoo.com/question/index?qid=2008060315202AAYdiJW

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