Motion The process of changing from one position to another
Speed How fast an object changes position Speed= Distance/Time
Calculating Speed Julie ran from her house on Ridge Road to Lincoln School; which is 2 miles away. It took her 20 minutes to get there; what was her speed in miles per minute? 2 miles/20minutes=0.1m/ min
Velocity Describes an object’s speed AND its direction
Free Fall Free fall- the motion of a falling object when the only force acting on it is gravity In free fall, the force of gravity is an unbalanced force, which causes an object to accelerate
Free Fall all objects in free fall accelerate at the same rate regardless of their masses!
Weight Mass- the amount of matter in an object Weight- measure of the force of gravity acting on an object Weight=mass x acceleration Gravity on Earth is 9.8m/sec 2
Calculating Weight Example: Calculate the mass of an object weighing 10kg: 10kg x 9.8m/s 2
Momentum A property that a moving object has because of its mass and velocity Momentum = Mass x Velocity
Calculating Momentum What is the momentum of a 5kg bowling ball rolling down a lane at a velocity of 7m/s? =5kg x 7 m/s =35kg x m/s
Law of Conservation of Momentum The total amount of momentum in a group of interacting objects does not change unless outside forces act on the objects
Newton’s Laws of Motion Isaac Newton not only studied Physics, but was the inventor of Calculus and one of History’s most famous scientists
Newton’s 1 st Law of Motion An object at rest will stay at rest, and an object in motion will continue to move in the same direction and the same speed unless acted upon by a force. “
1 st Law Example What are some examples of forces that might stop the object from moving? To make it move?
Inertia The tendency of a still or moving object to resist changes in motion
Newton’s Second Law of Motion An object acted on by a net force will accelerate in the direction of the force. The object’s acceleration equals the net force divided by the mass. Acceleration= Force/mass Force= mass x acceleration
2 nd Law Example A grocery cart that weighs 30 kg with a net force of 60N acting on it will accelerate at 2 m/s 2 because … acceleration = force/mass 60N/30kg= 2 m/s 2
Newton’s Third Law of Motion For every action force exerted on an object, the object will exert an equal and opposite reaction.
3 rd Law Example When you are swimming and you pull your arms through the water in one direction, your body moves in the opposite direction
Work Work- result of a force moving an object over a distance The unit of measurement for work is a joule Work= Force x Distance
Potential vs. Kinetic Energy Potential Energy Kinetic Energy
Power Power is the amount of work done in a period of time Power= Work/Time Remember: work is measured in joules and time is measured in seconds
Energy Energy- the ability to do work or cause change Kinetic energy- the energy an object has because it is moving Potential energy- stored energy
Thermal Energy Thermal energy, or heat, is the total energy of the movement of molecules in a substance
Heat Transfer There are three ways heat can be transferred: Convection Conduction Radiation Radiation is the transfer of energy via electromagnetic waves
Conduction Conduction is a situation where the heat source and heat sink are connected by matter.
Temperature vs. Heat Temperature Temperature is a measure of the average kinetic energy level of a substance Heat Heat is the total energy associated with the motion of molecules
Measuring Temperature Temperatur e can be measured in… Fahrenheit Celsius Kelvin
Fahrenheit Fahrenheit is the classic English system of measuring temperatures. Water freezes at 32 degrees Fahrenheit Water boils at 212 degrees
Celsius Celsius is the modern system of measuring temperature. The freezing point of water is 0 degrees Celsius the boiling point is 100 degrees Celsius
Formula Celsius=(Fahrenheit Temperature -32)*5/9
Thermal Expansion Thermal expansion is when gases expand as the temperature increases Think about it… Have you ever been hot and sticky and felt that your clothes seemed tighter or that your hand were swelling? This is an example of thermal expansion
Contraction The opposite of expansion is contraction A substance will contract when heat is removed If you remove enough heat from a gas it will become a liquid Liquids can turn into solids with further cooling