Physics Review Unit 3 Forces | Concordia University Wisconsin

University:
Concordia University Wisconsin
Course:
PHYS 1514 | General Physics I
Academic year:

2019
Views:

98

Pages:

6
Author:

Michael Haley

Unit 3: Forces - Freefall: An object in free-fall does not encounter air resistance and accelerate downwards. The acceleration due to gravity will cause it to speed up until it hits the ground. Newton’s Laws of Motion - 1st Law of Motion: An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an outside force. - Inertia: is the resistance of an object as it changes in its state of motion. An object’s inertia is dependent - - 2nd Law of Motion: The greater the mass of the object, the more force will be required to act upon it in order to accelerate the object. - 3rd Law of Motion: For every action force, there is an equal and opposite reaction force. Force: A push or a pull that is acted upon on an object that causes objects to interact. Force is a vector quantity that has magnitude and direction. When forces are balanced, there is no acceleration occurring. Force is measured in newtons (N). Equilibrium: When the net force acting on an object is at zero, the object is at equilibrium and thus experiencing no acceleration. Static equilibrium: The object is at rest. Dynamic Equilibrium: The object is moving at a constant velocity. Weight: The force of gravity that acts upon an object and is always directed toward the center of the earth. Weight is dependent on the planet that the object is on. Weight can vary depending on the planet it’s on. Weight is measured in newtons (N). Mass: A measure of inertia that remains the same universally. Mass is measured in kilograms (kg). Normal Force: is a contact force between the object and the surface that it’s interacting with. The normal force is perpendicular to the surface that it’s in contact with. Friction Force Principles of Friction: - The force of friction opposes the relative motion between two surfaces that are interacting. - Friction is dependent on the nature of the materials that is in contact with - The force of friction is directly proportional to the force pressing the two surfaces together, also known as the normal force Coefficient of Friction μ - Mu is a factor that offers an indication of how much friction exists between 2 materials. The larger the factor, the larger the force of friction. Static Friction - The force of friction between objects that are not sliding relative to each other. Static friction increases as more force is applied to the object. - Kinetic Friction - The force of friction between objects that are sliding against each other. Kinetic friction is dependent on Mu, the coefficient of friction, and the normal force. - Inclined Planes - For an object on an inclined plane or ramp, gravity is acting on the object and pulling it down as a result. The acceleration is dependent on the angle. At 90 degrees, free fall occurs. - On a frictionless inclined plane, F(n) and F(g) are acting on the object. Normal force is perpendicular to the surface. Gravity points straight down towards the Earth and the object will move parallel to the ramp. - Uniform Circular Motion Centripetal force: causes an object to take a circular path. During uniform circular motion, the speed stays constant, but the direction changes. The change in direction is caused by centripetal force. Centripetal force always points towards the center. Centripetal force arises from both tension and gravity. -