Scaler Quantity (definition and examples) Average speed. (definition and examples)

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1 Newton s First Law Newton s Second Law Newton s Third Law Vector Quantity Scaler Quantity (definition and examples) Average speed (definition and examples) Instantaneous speed Acceleration

2 An object at rest remains at rest, an object in motion remains in motion if net force acting on them equals 0. (acceleration =0) Vector quantity has both magnitude and direction Examples: velocity, acceleration, Force For every action there is an equal and opposing reaction Scaler quantity magnitude only (no direction involved) Average speed = v = d t Examples: mass, speed, temperature, distance a = v t Acceleration = change in velocity divided by change in time (time interval) Your speed at that moment (instant).

3 Momentum Kinetic energy Potential energy (gravitational potential energy) Friction Weight Work Units for mass Units for energy

4 Energy in motion Potential energy is converted into kinetic energy when object falls Momentum = mass x velocity (is a conserved quantity) m = p = mv p v v = p m Force that acts in opposite direction to motion (due to irregularities in surfaces Energy given to object that is elevated against gravity (lifted up) = mass x g x height E = mgh Work = force x distance W = Fd Work done lifting an object equals in gravitational potential energy gained. = force of gravity = mass x gravity (mg) F g = mg Joules (J) Used for: Work, KE & PE Kilograms (kg) Mass remains constant every where in the universe. You mass is the same on earth or the moon (your weight will change howeverweight = mg

5 Units for acceleration Units for Force Centripetal Force Velocity vs. speed Gravitational Force (effect of mass and distance) Elastic collision Inelastic collision Law of Conservation of Energy

6 Newtons (N) = kg x m/s 2 Meters per second squared m s 2 Velocity - vector quantity Speed - scaler quantity Velocity will change is either speed or direction change Means centerseeking force. Always points to the center of the circle Objects bounce off each other Mo heat or deformation during contact double mass = double F double distance = 1/4 F Force of attraction Object stick together after collision Total energy = PE + KE

7 Law of Conservation of Momentum 1 KE = mv 2 2 E = mgh p = mv d v = F g = mg t 1 F d 2 F = ma

8 Kinetic Energy (energy in motion) Double mass = doubles KE Double velocity = 4x KE momentum before = momentum after Momentum (inertia in motion) Double mass = doubles p Double velocity = doubles p Gravitational Potential Energy (stored energy) Double mass = doubles PE Double height = doubles PE Force of gravity = weight = mass x gravity (your weight different on other planets) Average velocity d ( d1 d0 ) v = = t t t When initial distance and time are 0 = ( ) 1 0 v = d t Newton Second law a = F m m = F a Inverse square law Applies to force of gravity and the distance between two objects Double distance then force = 1 =

9 Assuming there is no air resistance, what values would increase, decrease or remain constant as a object falls? Describe projectile motion (what are vertical and horizontal components and how to they change during trajectory? Impulse Uniform circular motion Vector sum Net Force v = v = 0 gt

10 Increase: velocity, speed, momentum, kinetic energy Constant: acceleration Horizontal never changes Vertical velocity changes constantly Vertical velocity = 0 at top or trajectory Decreases: Potential energy Impulse = force x time = change in momentum mv = Ft More swing-through (time) more impulse Longer gun barrel (time) more impulse Decrease impulse by decreasing force or time Particle model A - at rest B - constant velocity C - acceleration D - deceleration Uniform accelerated motion Final velocity = initial velocity + gravity x time Sum or all forces acting on system Use to calculate velocity of dropped object when it hits the groung

11 Temperature Scales What are the 3 different scales and how are each related? Thermal Expansion Difference between Temperature and Heat Bimetallic Strip Temperature And Kinetic Energy Methods of Heat Transfer Specific Heat Laws of Thermodynamics

12 When temperature of substance isincreased, its molecules jiggle faster and normally tend to move farther apart. Bimetallic strip two strips of different metals (say one of brass and the other of iron) When heated- different expansion causes strip to bend into a curve; (used in thermostats) Temperature is related to the random motions of the molecules in a substance Heat The energy that is transferred from one object to another because of a temperature difference between them Conduction-transfer of heat within and between materials that are in direct contact Convection-transfer of energy by movement of hotter substance (like in fluids or air) Radiation-the transfer of energy by electromagnetic waves (like fire or the sun s rays) Temperature is related to the random motions of the molecules in a substance. Hotter=faster Faster=more kinetic energy First Law restatement of law of conservation of energy Second law- heat will never of itself flow from a cold object to a hot object Entropy- a measure of disorder (objects tend to become more disordered. More disorder=more entropy) Specific Heat quantity of heat required to raise the temperature of a unit mass of the substance by 1 degree. Water has very high specific heat (takes a lot energy to heat up or to cool down