Presentation on theme: "Motion Speed Vectors Acceleration"— Presentation transcript:
1Motion Speed Vectors Acceleration Distance, Time, and Acceleration Free Fall System Air Resistance First Law of MotionMassSecond Law of MotionMass and WeightThird Law of MotionCircular MotionNewton's Law of GravityArtificial Satellites
2Isaac NewtonNewton's laws of motion are three physical laws which provide relationships between the forces acting on a body and the motion of the body.They were first compiled by Sir Isaac Newton in 1687.
3Sir Isaac Newton’s Three Laws of Motion- 1687 Every object in a state of uniform motion tends to remain in that state of motion unless an external force is applied to it. "A particle will stay at rest or continue at a constant velocity unless acted upon by an external unbalanced net force.“Click here for a video clip.
4Newton’s 2nd LawII. The relationship between an object's mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors (as indicated by their symbols being displayed in slant bold font); in this law the direction of the force vector is the same as the direction of the acceleration vector. "F = ma: the net force on an object is equal to the mass of the object multiplied by its acceleration.“ Click here for a video clip.
5Newton’s 3rd LawIII. For every action there is an equal and opposite reaction. Click here for a video clip.
6Speed Definitions: v = d/t Speed General formula for speed: The rate at which something moves a given distance.Faster speeds = greater distancesGeneral formula for speed:Speed = distance / timeAbbreviations commonly used:d = distance t = time v = speedv = d/t
14Free FallThe acceleration of gravity (g) for objects in free fall at the earth's surface is 9.8 m/s2.Galileo found that all things fall at the same rate.
15Free Fall The rate of falling increases by 9.8 m/s every second. Height = ½ gt2For example:½ (9.8 )12 = 4.9 m ½(9.8)22 = 19.6 m½ (9.8)32 = 44.1 m½ (9.8)42 = 78.4 m
16Free FallA ball thrown horizontally will fall at the same rate as a ball dropped directly.
17Free FallA ball thrown into the air will slow down, stop, and then begin to fall with the acceleration due to gravity. When it passes the thrower, it will be traveling at the same rate at which it was thrown.
18Free FallAn object thrown upward at an angle to the ground follows a curved path called a parabola.
19Air Resistance In air… In a vacuum A stone falls faster than a feather Air resistance affects stone lessIn a vacuumA stone and a feather will fall at the same speed.
20Air Resistance Free Fall A person in free fall reaches a terminal velocity of around 54 m/sWith a parachute, terminal velocity is only 6.3 m/sAllows a safe landing
21Air Resistance Ideal angle for a projectile In a vacuum, maximum distance is at an angle of 45oWith air resistance (real world), angle is lessBaseball will go furthest hit at an angle of around 40o
22First Law of MotionThe first law of motion states: If no net force acts on it, an object at rest remains at rest and an object in motion remains in motion at a constant velocity.
23MassInertia is the apparent resistance an object offers to any change in its state of rest or motion.
24Second Law of Motion F = Ma Newton's second law of motion states: The net force on an object equals the product of the mass and the acceleration of the object. The direction of the force is the same as that of the acceleration.F = Ma
25Second Law of MotionA force is any influence that can cause an object to be accelerated.The pound (lb) is the unit of force in the British system of measurement:1 lb = 4.45 N (1 N = lb)
26Mass and WeightWeightDefinition: The force with which an object is attracted by the earth’s gravitational pullExample: A person weighing 160 lbs is being pulled towards the earth with a force of 160 lbs (712 N).Near the earth’s surface, weight and mass are essentially the same
27Third Law of MotionThe third law of motion states: When one object exerts a force on a second object, the second object exerts an equal force in the opposite direction on the first object.
29Circular MotionCentripetal force is the inward force exerted on an object to keep it moving in a curved path.Centrifugal force is the outward force exerted on the object that makes it want to fly off into space.