{"id":13,"date":"2017-08-18T07:20:06","date_gmt":"2017-08-18T07:20:06","guid":{"rendered":"http:\/\/americanboard.org\/Subjects\/chemistry\/?page_id=13"},"modified":"2017-10-13T06:47:39","modified_gmt":"2017-10-13T06:47:39","slug":"general-science-knowledge-ii","status":"publish","type":"page","link":"https:\/\/americanboard.org\/Subjects\/chemistry\/general-science-knowledge-ii\/","title":{"rendered":"General Science Knowledge II"},"content":{"rendered":"
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\u2b05 Previous Lesson<\/a>\u00a0Workshop Index<\/a>\u00a0Review \u27a1<\/a><\/p>\n<\/div>\n

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General Science Knowledge II<\/h1>\n

Lesson Objective<\/h4>\n

In this lesson we will review general science knowledge including, but not limited to, Newton\u2019s laws of motion, understanding the properties of electromagnetic waves and explaining the basic functions and structures of DNA and RNA<\/p>\n

Previously we covered…<\/h4>\n
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  • Describing the difference between mass and weight<\/li>\n
  • Explaining compounds and mixtures using heterogeneous and homogenous examples<\/li>\n
  • Relating matter, atoms, elements, molecules, and ions<\/li>\n
  • Distinguishing between ionic and molecular compounds<\/li>\n
  • Reviewing molecular movement of the three main states of matter<\/li>\n
  • Analyzing a phase diagram<\/li>\n<\/ul>\n
    Newton’s Second Law<\/abbr> states the unbalanced force acting on an object equals the object\u2019s mass times its acceleration. Consider rolling a ball down a hill. A beach ball would have less force than a bowling ball. The mass of the ball times its acceleration would give it much more force than a beach ball. However, if the forces are balanced, then there is no acceleration.<\/p>\n

    Motion and Forces<\/h3>\n

    Motion<\/abbr> is the ability to move or change position. Force<\/abbr> is the influence on a system that causes a change in position or velocity<\/abbr>. Motion is directly related to force. One cannot exist without the other. Both motion and force were described and explained by Sir Isaac Newton. Newton studied forces and motion and developed theories about them. In time, those theories were changed to law and are the foundation of physics classes around the world. Newton’s First Law states that an object at rest remains at rest and an object in motion maintains its velocity unless either object experiences an unbalanced force. We experience this law daily whenever we ride in a car. As the car comes to a stop, we move forward. Our muscles, seat belt and the friction between us and the seat stop our forward momentum<\/abbr>. The opposite situation occurs when the car begins traveling again. The car will move forward and we will slide back. This is a daily demonstration of Newton\u2019s first law.<\/p>\n\n\n\n
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    Newton\u2019s Second Law<\/strong><\/p>\n

    Force = mass \u00d7 acceleration
    \nF = ma <\/em><\/p>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    Sample Problem<\/h3>\n

    Paramedics lift a stretcher that is holding a person. The total mass of the stretcher and the person is 175 kg. The paramedics lift the stretcher at an upward acceleration of 0.425 m\/s2<\/sup>. What is the unbalanced force necessary to produce this acceleration of the person and the stretcher?<\/p>\n