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Physical ScienceUnit 1Motion
Mass• Amount of matter in an object
• Units: kilogram (or gram)
• Measured:– Using a balance
Volume• Amount of space taken up by an object
• Units: m3 or ml
• Measured:– Regular object: length X width X height– Irregular object: water displacement
Density
• Ratio of an object’s mass to its volume
• Units: kg/m3
• Calculated: Density=mass/ volume
Density = Mass/ Volume• 1. 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?
• 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?
States of Matter• Solids- have a definite shape and volume
– Atoms are packed close together in a regular pattern
• Liquids- definite volume but shape may change– Atoms are close together but their arrangement is
more random
• Gases- no definite volume or shape– Atoms are arranged randomly with more space
between them.
• Plasma- exists at very high temperatures
Kinetic Theory• States that all particles of matter are in
constant motion– Solids
• Particles vibrate around fixed locations; no visible motion
– Liquids• Liquid takes shape of its container because atoms can
flow but they maintain their volume because the forces of attraction keep the particles close together
– Gases• Particles in a gas are in constant, random motion• Motion of one particle is unaffected by the motion of
other particles unless the particles collide.• Forces of attraction can be ignored under ordinary
conditions.
• Pressure– Result of a force distributed over an area
• Unit: Pa (pascal); N/m2
• Temperature– Average amount of kinetic energy
• Factors that affect pressure– Temperature
• Raising temperature will increase the pressure (increase motion)
– Volume- reducing volume increases pressure
Gas Laws• Charles’s Law
– Volume of a gas is directly proportional to its temperature
• If temperature increases, volume increases
• V1/T1= V2/ T2
• Boyle’s Law– Volume of a gas is inversely
proportional to its pressure• If volume decreases pressure
increases
• P1V1= P2V2
Phase Diagrams• Lets you work out which
exact phases are present at any give temperature and pressure– Melting- from solid to liquid– Freezing- from liquid to solid– Vaporization- from liquid to
gas– Condensation- from gas to
liquid– Sublimation- from solid to gas– Deposition- from gas to solid
Phase Change
• Draw a phase change diagram. Be sure to include the following: solid, liquid, gas, temperature, pressure.
• On the phase diagram, label the 6 phase changes.
Distance and Displacement
• Frame of Reference
• Relative Motion– Movement based on frame of reference
• Distance– Length of a path between two points– SI unit is meter (m); may use km or cm
Speed And Velocity
• Speed- how fast an object moves– Speed= distance/time– SI unit of speed is m/s
• Constant speed- doesn’t change• Average speed- speed varies (distance divided by
time)
• Velocity- describes both the speed and direction of a moving object
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?
Speed• Speed can be determined using a graph
on which distance is plotted at various times– Slope is a measure of steepness– The faster the speed of an object, the greater
the slope of the line on its distance vs. time graph
– When speed =0 or object is not moving, the line is horizontal
Acceleration
• The rate at which velocity changes
• Can be a change in direction and/or speed
• Calculating acceleration– Acceleration= change in velocity/ total time
Graphs of Acceleration• The slope of a speed- time graph is
acceleration.
• Positive Acceleration
• Negative Acceleration
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?
Force
• Push or pull that acts on an object
• SI unit= Newton (N)
• Or 1kg*m/s2
• An arrow can be used to represent strength and direction of force
• Combining Forces– Forces can be added
together; creates net force = -------->
• Balanced Forces– The overall net force is
zero =0
• Unbalanced Forces– Causes movement in the
direction of the greater force-------- = ---
Friction• Force that
opposes motion of objects as they move past each other– Four basic kinds
• Static• Sliding• Rolling• Fluid
– Air resistance
• Gravity• Force that acts
between two masses
Newton• Newton’s 1st 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 inertia• Newton’s 2nd Law of
Motion– Acceleration 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
Practice Problems• An 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?
Weight and Mass• Weight is the force of
gravity acting on an object– Weight= mass X
acceleration due to gravity
• W=mg (g= 9.8m/s2)
• Mass is a measure of the inertia of an object
• Unit for weight is N • Unit for mass is Grams
Astronaut on EarthMass= 88kg; Weight= 863 N
Astronaut on MoonMass = 88kg; Weight= 141N
Newton’s 3rd Law
• When 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.
Momentum• Momentum is the product of an object’s
mass and its velocity.
• Momentum= Mass X velocity
• Unit = kg*m/s
Practice Momentum Problems
• A 75 kg speed skater moving forward at 16m/s.
• A 135 kg ostrich running north at 16.2 m/s
• A 5.0 kg baby on a train moving eastward at 72m/s.
• A 0.8kg kitten running to the left at 6.5 m/s
• A 48.5kg passenger on a train stopped on the tracks.
