Unit Two: Force and Motion
1st Prep. Science
2nd Term
Unit Two: Force and Motion Lesson One: Universal Forces in Nature Force: (Its measuring unit is Newton). It is an effect attempts to change the object’s phase from being static to motion or vice versa or attempts to change the direction of motion. All forces can be divided into main four divisions which are: 1. Attraction forces: [Ex: Earth’s gravity force to objects]: Object’s weight: It is the ability of the Earth to attract that object to its center. Or It is the force of Earth’s gravity on the object. Object’s center of gravity: It is the point at the center of the object at which the force of gravity affects the object. ( ) ( ) ( ). 2 (Newton) (Kg) (9.8 10 m/s ).
2. Electromagnetic forces: It is the magnetic force produced by the effect of passing an electric current through a coil. Application on electromagnetic forces: a. Electromagnet: It is made up of an isolated copper wire coiling around a bar of wrought iron. It changes the electric energy into magnetic energy. Its uses: 1. Electric winches which lift scrap iron and cars in ports. 2. Electric bells. b. Electric generator (The dynamo): It is used in converting the mechanical energy into electric energy. c. Electric motor: It is used in converting the electric energy into mechanical energy. 3. Weak nuclear forces: Used in: a. Medicine. b. Scientific researches. c. Industry. 4. Strong nuclear forces: Used in: a. Producing electric energy. b. Military purposes.
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2nd Term
Unit Two: Force and Motion Lesson One: Universal Forces in Nature Force: (Its measuring unit is Newton). It is an effect attempts to change the object’s phase from being static to motion or vice versa or attempts to change the direction of motion. All forces can be divided into main four divisions which are: 1. Attraction forces: [Ex: Earth’s gravity force to objects]: Object’s weight: It is the ability of the Earth to attract that object to its center. Or It is the force of Earth’s gravity on the object. Object’s center of gravity: It is the point at the center of the object at which the force of gravity affects the object. ( ) ( ) ( ). 2 (Newton) (Kg) (9.8 10 m/s ).
2. Electromagnetic forces: It is the magnetic force produced by the effect of passing an electric current through a coil. Application on electromagnetic forces: a. Electromagnet: It is made up of an isolated copper wire coiling around a bar of wrought iron. It changes the electric energy into magnetic energy. Its uses: 1. Electric winches which lift scrap iron and cars in ports. 2. Electric bells. b. Electric generator (The dynamo): It is used in converting the mechanical energy into electric energy. c. Electric motor: It is used in converting the electric energy into mechanical energy. 3. Weak nuclear forces: Used in: a. Medicine. b. Scientific researches. c. Industry. 4. Strong nuclear forces: Used in: a. Producing electric energy. b. Military purposes.
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