Reading Assignment #1: Vector Analysis
Textbook Sections that I read: 2.1-3
• An interaction between two objects can be described and measured in terms of two forces. The force is a push or either a pull.
• There are two types of forces. #1 is a long range force and this force does not require the objects involved to be touching each other. An example of this is when you are holding a magnet away from a refrigerator and you are able to feel the magnetic pull. #2 is a contact force and this occurs only when the objects are touching one another.
• A vector in physics is another name for a force. All vectors have a direction in space and magnitude as well. Both ...view middle of the document...
The net force is the vector sum of all the forces that are acting on the object.
• Newton’s first law says that an object acted on by zero net force moves in a straight line with constant speed or it remains at rest if it was at rest.
• Velocity vector is a measurement of both speed and the direction of an objects motion.
• There is no force required to keep an object in motion as long as there are no forces that oppose its motion.
• Inertia means resistance to changes in velocity. Newton’s first law can also be called the law of inertia.
Reading Assignment Questions:
Explain the need for automobile seat belts in terms of Newton’s first law. Newton’s first law is an object in motion tends to stay in motion unless acted on by an opposing force. A car and seatbelts are connected together where the car goes the seatbelts go. The people in the car are not connected to the car. That is why they must be strapped in by the seatbelts. If the car had an accident of slammed on brakes really hard everyone would stay in motion that the car was in. Because the seatbelts are there to keep people in the same motion in the car it keeps a lot of people from being slung through the windshield.
A freight train consists of an engine and several identical cars on level ground. Determine whether each of the statements is correct or incorrect and explain why. (a) If the train is moving at constant speed, the engine must be pulling with a force greater than the train’s weight. False the engine would have to be pulling with the same force as the trains’ weight. (b) if the train is moving at constant speed, the engine’s pull on the first car must exceed that car’s backward pull on the engine. True, if the engines pull did not exceed the backward pull of the first car the weight of the other cars would cause the train to not be able to maintain constant speed. (c) If the train is coasting, its inertia makes it slow down and eventually stop. False, the friction of the trains wheels and tracks would be what caused it to slow down.
Reading Assignment #3: Newton’s Third Law
Textbook Sections that I read: 2.5
• Every force is part of an interaction between two objects and each of those objects exerts a force on the other. These forces are called an interaction pair; each of these forces is partners with one another.
• Newton’s third law of motion says that interaction partners always have the same magnitude and are in the opposite direction.
• Interaction partners are always of the same type.
• All the parts of an object make up the system.
• All the interactions that affect the system must be either internal or external.
• To find the net force on the system, ignore all the internal forces and add the external forces.
Reading Assignment Questions:
If a wagon starts at rest and pulls back on you with a force equal to the force you pull on it, as required by Newton’s third law, how is it possible for you to make the wagon start...