7 Density Ratio of an object’s mass to its volume Units: kg/m3 Calculated: Density=mass/ volume
8 Density = Mass/ Volume1. What is the density of carbon dioxide gas if .196g occupies a volume of 100ml?2. A block of wood 3.0 cm on each side has a mass of 27 g. What is the density of this block?3.An irregular shaped stone was lowered into a graduated cylinder holding a volume of water equal to 2.0mL. The height of the water rose to 7.0mL. If the mass of the stone was 25g, what was its density?
9 4. A 10. 0cm3 sample of copper has a mass of 89. 6g 4. A 10.0cm3 sample of copper has a mass of 89.6g. What is the density of copper?5. Silver has a density of 10.5 g/cm3 and gold has a density of 19.3 g/cm3. Which would have a greater mass, 5 cm3 of silver or 5 cm3 of gold?6. Five ml of ethanol has a mass of 3.9 g, and 5.0 ml of benzene has a mass of 4.4g. Which liquid is denser?7. A sample of iron has the dimensions of 2cm X 3cm X 2cm. If the mass of this rectangular shaped object is 94 g, what is the density of iron?
10 States of Matter Solids- have a definite shape and volume Atoms are packed close together in a regular patternLiquids- definite volume but shape may changeAtoms are close together but their arrangement is more randomGases- no definite volume or shapeAtoms are arranged randomly with more space between them.Plasma- exists at very high temperatures
11 Kinetic TheoryStates that all particles of matter are in constant motionSolidsParticles vibrate around fixed locations; no visible motionLiquidsLiquid takes shape of its container because atoms can flow but they maintain their volume because the forces of attraction keep the particles close togetherGasesParticles in a gas are in constant, random motionMotion of one particle is unaffected by the motion of other particles unless the particles collide.Forces of attraction can be ignored under ordinary conditions.
12 Factors that affect pressure Result of a force distributed over an areaUnit: Pa (pascal); N/m2TemperatureAverage amount of kinetic energyFactors that affect pressureRaising temperature will increase the pressure (increase motion)Volume- reducing volume increases pressure
13 Gas Laws Charles’s Law Boyle’s Law Volume of a gas is directly proportional to its temperatureIf temperature increases, volume increasesV1/T1= V2/ T2Boyle’s LawVolume of a gas is inversely proportional to its pressureIf volume decreases pressure increasesP1V1= P2V2
14 Phase DiagramsLets you work out which exact phases are present at any give temperature and pressureMelting- from solid to liquidFreezing- from liquid to solidVaporization- from liquid to gasCondensation- from gas to liquidSublimation- from solid to gasDeposition- from gas to solid
15 Phase ChangeDraw a phase change diagram. Be sure to include the following: solid, liquid, gas, temperature, pressure.On the phase diagram, label the 6 phase changes.
16 Distance and Displacement Frame of ReferenceRelative MotionMovement based on frame of referenceDistanceLength of a path between two pointsSI unit is meter (m); may use km or cm
17 Speed And Velocity Speed- how fast an object moves Speed= distance/timeSI unit of speed is m/sConstant speed- doesn’t changeAverage speed- speed varies (distance divided by time)Velocity- describes both the speed and direction of a moving object
18 Practice Speed and Velocity A ship travels 200 km in 4 hours. Calculate the velocity.A horse began running due east and covered 25km in 5 hrs. What is the average velocity of the horse?What is the velocity in meters per second of a runner who runs exactly 110 m toward the beach in 72 seconds?
19 SpeedSpeed can be determined using a graph on which distance is plotted at various timesSlope is a measure of steepnessThe faster the speed of an object, the greater the slope of the line on its distance vs. time graphWhen speed =0 or object is not moving, the line is horizontal
20 Acceleration The rate at which velocity changes Can be a change in direction and/or speedCalculating accelerationAcceleration= change in velocity/ total time
21 Graphs of Acceleration The slope of a speed- time graph is acceleration.Positive AccelerationNegative Acceleration
22 Practice Acceleration A car accelerates from 0m/s to 45 m/s northward in 15 s. What is the acceleration of the car?After reaching 45 m/s, the car slows down to 0 m/s in 10.0s. What is the acceleration of the car?
23 Force Push or pull that acts on an object SI unit= Newton (N) Or 1kg*m/s2An arrow can be used to represent strength and direction of force
24 Combining Forces Balanced Forces Unbalanced Forces Forces can be added together; creates net force = >Balanced ForcesThe overall net force is zero =0Unbalanced ForcesCauses movement in the direction of the greater force = ---
25 FrictionForce that opposes motion of objects as they move past each otherFour basic kindsStaticSlidingRollingFluidAir resistanceGravityForce that acts between two masses
26 Newton Newton’s 1st Law of Motion Newton’s 2nd Law of Motion An object at rest stays at rest and an object in motion remains in motion unless it experiences an unbalanced force.Law of inertiaNewton’s 2nd Law of MotionAcceleration of object is equal to the net force acting on it divided by the object’s mass.Acceleration= net force/ Mass or a=F/m
27 Practice ProblemsAn automobile with a mass of 1000 kilograms accelerates when the traffic light turns green. If the net force on the car is 4000 N, what is the car’s acceleration?A boy pushes forward a cart of groceries with a total mass of 40.0 kg. What is the acceleration of the cart if the net force on the cart is 60.0 N?An automobile with a mass of 1200kg accelerates at a rate of 3.0 m/s2 in the forward direction. What is the net force acting on the automobile?
28 Weight and Mass Weight is the force of gravity acting on an object Weight= mass X acceleration due to gravityW=mg (g= 9.8m/s2)Mass is a measure of the inertia of an objectUnit for weight is NUnit for mass is GramsAstronaut on EarthMass= 88kg; Weight= 863 NAstronaut on MoonMass = 88kg; Weight= 141N
29 Newton’s 3rd LawWhen one object exerts a force on a second object, the second object exerts an equal and opposite force on the first object. (Action- Reaction Forces)Action- reaction forces propel the swimmer through the water. The swimmer pushes against the water and the water pushes the swimmer ahead.
30 Momentum Momentum is the product of an object’s mass and its velocity. Momentum= Mass X velocityUnit = kg*m/s
31 Practice Momentum Problems A 75 kg speed skater moving forward at 16m/s.A 135 kg ostrich running north at 16.2 m/sA 5.0 kg baby on a train moving eastward at 72m/s.A 0.8kg kitten running to the left at 6.5 m/sA 48.5kg passenger on a train stopped on the tracks.