* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download - St. Aidan School
Survey
Document related concepts
Newton's theorem of revolving orbits wikipedia , lookup
Relativistic mechanics wikipedia , lookup
Coriolis force wikipedia , lookup
Modified Newtonian dynamics wikipedia , lookup
Hunting oscillation wikipedia , lookup
Velocity-addition formula wikipedia , lookup
Fictitious force wikipedia , lookup
Equations of motion wikipedia , lookup
Faster-than-light wikipedia , lookup
Classical mechanics wikipedia , lookup
Centrifugal force wikipedia , lookup
Classical central-force problem wikipedia , lookup
Length contraction wikipedia , lookup
Work (physics) wikipedia , lookup
Transcript
Motion Chapter 9 Reference Point – is a place or object used for comparison to determine if something is moving. SI units - scientists use the International System of Units to describe the distance an object moves. Section 2 Calculating Speed Speed = Distance/Time Instantaneous speed - rate at which an object is moving at a given instant in time. Velocity - speed in a given direction. If you know both the speed and direction of an object’s motion, you know the velocity of the object. Calculating Slope: Slope = Rise/Run Rise is the vertical difference between any two points on the line. The run is the horizontal difference between the same two points. Section 3 Acceleration - the rate at which velocity changes (“the process of speeding up”). Increasing speed Decreasing speed Change in direction. Increasing Speed whenever an object’s speed increases, the object accelerates. Decreasing Speed - slow down or decelerate. Changing Direction - an object can change direction as well as change speed. Calculating Acceleration Final speed – Initial speed Time Chapter 10 Force - A push or pull. Described by its strength and by the direction in which it acts. Measured in (N) Newton’s Unbalanced Forces can cause an object to start moving, stop moving, or change direction. Balanced Forces are equal forces acting on one object in opposite directions. It does not change the objects motion. (P. 336) Section 2 Friction - the force two surfaces exert on each other when they rub against each other. There are 4 types of Friction: 1. Static Friction acts on objects that are not moving. 2. Sliding Friction is when two solid surfaces slide over each other. 3. Rolling Friction is when an object rolls across a surface. 4. Fluid Friction is when a solid object moves through a fluid. Gravity -a force that pulls objects toward each other. The law of Universal Gravitation states that the force of gravity acts between all objects in the universe. MASS and DISTANCE are the two factors that affect this. Mass is a measure of the amount of matter in an object. Weight is a measure of the gravitational force exerted on an object. Free Fall -when the only force acting on an object is gravity. (In the absence of air, two objects with different masses fall at exactly the same rate. P. 346) *Near the surface of Earth, the acceleration due to gravity is 9.8m/s2 Air Resistance - objects falling through air experience this type of fluid friction. Projectile Motion –is the motion of an object that is thrown. Section 3 Newton’s Law’s of Motion 1st Law- an object at rest will remain at rest, and an object moving at a constant velocity will continue moving at a constant velocity, unless it is acted upon by an unbalanced force. This is known as Inertia (an object resistance to change in motion.) 2nd Law - acceleration depends on the object’s mass and on the net force action on the object. Acc = Net force/mass Sec.4 3rd Law -if one object exerts a force on another object, then the second object exerts a force of equal strength in the opposite direction on the first object. For every action there is an equal but opposite reaction. Momentum -characteristic of a moving object that is related to the mass and the velocity of the object. Momentum = Mass x Velocity Law of Conservation of Momentum - in the absence of outside forces, the total momentum of objects that interact does not change. Section 5 Rockets and Satellites A rocket can rise into the air because it expels gases with downward action force. It exerts an equal but opposite reaction force on the rocket. A satellite is any object that orbits another object in space. Centripetal force – is any type of force that causes an object to move in a circular path.