The Important Topics of Physics Essay Example For Students

The Important Topics of Physics Essay Topic #5(. Forces 1 . Forces 2. Newtons First Law of Motion 3. Newtons Second Law of Motion 4. Units of Force 5. Mass and Weight 6. Two Ways to Measure Mass 7. Friction 8. Net Force and Acceleration 9. Free Fall 10. Newtons Third Law of Motion *11. Forces on Inclined Planes Notes should include: Defend: Dynamics is defined as the study of the effects of forces on matter. Forces: Often a force is described as a push or a pull. Forces are often categorized according to the circumstances where they are observed to occur. For example forces are often categorized as gravitational, electromagnetic, or nuclear, though there are implore forces such as you, yourself doing something such as pushing down on your desk or bench top. The unit of force is the pound in the British (English) System and is the Newton in the Metric system. The symbol for the pound is lb and the symbol for the Newton is N. Newtons First Law of Motion: In the early sasss Galileo studied the motion off ball on an inclined plane. He noticed that as the ball rolled down the ramp due to gravity, the balls velocity increased at a steady rate. He observed uniform acceleration. He also noticed that when the ball reached the bottom of the incline it moved across the lorry with a fairly constant velocity. He figured that on a perfectly smooth floor that went on infinitely the ball would never stop, but roll forever. Galileo concluded that there is a tendency for an object to resist a change in its motion. He gave us the concept of inertia. Inertia is defined as the tendency for an object to continue in the same motion it has been experiencing right along. Along came Isaac Newton, who was born the same year that Galileo died. He derived three laws of motion, which were built upon Goalies work. Newtons First Law of Motion states an object either mains at rest or in a state of constant velocity if it is not being acted upon by an unbalanced force. When all forces acting on an object are in a state of balance there is no acceleration. Thus acceleration is caused by an unbalanced force. You should know that the net force (symbol FINE) is the sum of all forces acting on an object. When this net force equals zero the sum of all forces acting on an object equals zero. Magnitude larger than zero, or not zero. To summarize, if the net force is equal to zero Newtons (or pounds), all forces acting upon the object are balanced and there is o acceleration. Newtons Second Law of Motion: Newton recognized that an unbalanced force is required, if an object is going to experience acceleration. For example, if you push on a piece of furniture with exactly the same amount of effort as someone else who is pushing in the dire ction opposite to your pushing, the object will not move. To move from rest the object has to experience acceleration. For the object to experience acceleration it has to experience an unbalanced force. The FINE experienced by the object is NOT zero. (Newtons Second Law is often described by the equation F = m a. His second law says that when an unbalanced force acts on an object, the object will experience acceleration proportional to the size of the unbalanced force. The direction of the acceleration will be the same as the direction of the force. In this equation F is the net force (FINE), the unbalanced force that causes the acceleration. As the equation shows this force is the product of mass and acceleration. Units of Force: The unit used to express force measurements is the Newton. It is abbreviated as a capital N. The dimensional analysis of this equation tell us that 1 N 1 keg m/so. This means that 1 N of force is equal too 1 keg mass accelerating at 1 m/ Mass and Weight: Mass measures the amount of matter of which an object is made. Weight is the measure of the force of gravity acting on the object. Weight is a function of position. Flight Of The Phoenix EssayThe coefficient of either type of friction is found experimentally by dividing the force of friction between two surfaces by the normal force pushing them together. NOTE: Friction should not be confused with inertia. It is not the same. Inertia exists tit or without the presence of friction. Free Fall: When an object moves through the atmosphere it experiences air resistance. When an object experiences free fall the object can strike enough air molecules as it falls that it is experiencing an upward force equal to but opposite in and continues to move downwards with a constant velocity. This velocity is called a terminal velocity. In a vacuum this could never happen and the object would continue to experience acceleration all the way to the ground. This concept also helps us explain the fact that leaves and pieces of paper do not appear to fall onwards as fast as heavier objects such as cinder blocks even though both are being accelerated downwards at the same rate. The difference is due to air resistance. In a vacuum, that is, where there is no air resistance, the leaves and pieces of paper would fall Just as fast as the cinder blocks. Of course that doesnt mean that a cinder block landing on you wouldnt hurt more than a single leaf. After all, the cinder block does have a much bigger mass than the leaf and therefore a much bigger force of gravity acting on it than is acting on the leaf. It is that greater Orca that will give you the headache or worse. Do you think a single leaf hitting you as it free fell in a no air resistance environment might hurt more than the same leaf falling from the same height in a normal air resistance environment? The answer is yes, it might sting a little, because though it has a low mass it is falling faster than it would in air. Newtons Third Law of Motion: Often you will hear someone refer to Newtons third law as the law of action and reaction. Newtons Third Law of Motion can be defined as every force is accompanied by an equal but opposite force. No single force acts on single object. A few examples are: ; Two charged objects either attract or repel one another. ; Two magnets either attract or repel one another. You attract the earth due to your mass at the same time the earth attracts you because of its mass. (Forces on Inclined Planes: If you use trigonometry you can deal with forces acting on objects that are positioned on inclined planes. For example, if an object of a certain mass is positioned on a ramp set at a certain angle B, both the normal force that presses it against the ramp (it will be less than its own weight because of the incline) ND the parallel force that causes it to slide down the ramp can be found by using the cosine of the angle and the sine of the angle respectively. Trigonometry will be studied in the next unit of study, so you can learn to solve problems involving forces in two dimensions. Vocabulary: Free Body Diagram, Force, Applied Force, Net Force, Force of Friction, Force of Gravity, Weight, Displacement, Position, Velocity (constant, average, instantaneous), Acceleration (constant, average, instantaneous), Air Resistance and Terminal Velocity as well as variable symbols. Skills to be learned: