Building Science Champions

Do you believe this picture shows a balanced or unbalanced force. Explain your answer in three sentences. Do you believe this picture shows a balanced or unbalanced force. Explain your answer in three sentences.

Explain how balanced and unbalanced forces are related to motion Explain how balanced and unbalanced forces are related to motion State Newton’s first law of motion State Newton’s first law of motion Define inertia Define inertia

Force Force Net force Net force Unbalanced force Unbalanced force Balanced force Balanced force Inertia Inertia

Force is either a push or a pull Force is either a push or a pull When one object pushes another, the first object is exerting force on the second object When one object pushes another, the first object is exerting force on the second object Force is not only described as how strong (magnitude), but also by direction Force is not only described as how strong (magnitude), but also by direction

Net force – the overall force on an object after all the forces are added together Net force – the overall force on an object after all the forces are added together Unbalanced force – can cause an object to start or stop moving, or change direction Unbalanced force – can cause an object to start or stop moving, or change direction 8N8N 8N8N 8N8N 8N8N 5 N 10 N

Balanced forces – equal forces acting on one object in opposite directions Balanced forces – equal forces acting on one object in opposite directions Balanced forces on an object will not change the objects acceleration, velocity or motion Balanced forces on an object will not change the objects acceleration, velocity or motion The sum of all forces equal 0 N The sum of all forces equal 0 N = 0 N 10 N 5N5N 5N5N 5N5N 5N5N

Balanced forces always equal 0 N and there is no change in motion Balanced forces always equal 0 N and there is no change in motion Unbalanced force are always > 0 N and there is a change in motion Unbalanced force are always > 0 N and there is a change in motion

Galileo Galilee, an Italian astronomer, first suggested that a force is needed to keep an object in motion Galileo Galilee, an Italian astronomer, first suggested that a force is needed to keep an object in motion Inertia – is the tendency of an object to resist change Inertia – is the tendency of an object to resist change If an object is moving it will continue to move If an object is moving it will continue to move If an object is not moving it will continue to be still If an object is not moving it will continue to be still Force is needed to change an objects inertia/motion Force is needed to change an objects inertia/motion Inertia The bus does not want to move, the force of the tourist is pushing the bus.

AN OBJECT AT REST WILL REMAIN AT REST AND AN OBJECT MOVING AT A CONSTANT VELOCITY WILL CONTINUE TO MOVE AT A CONSTANT VELOCITY UNLESS ACTED UPON BY AN UNBALANCED FORCE. AN OBJECT AT REST WILL REMAIN AT REST AND AN OBJECT MOVING AT A CONSTANT VELOCITY WILL CONTINUE TO MOVE AT A CONSTANT VELOCITY UNLESS ACTED UPON BY AN UNBALANCED FORCE. IMPORTAN T

Newton’s first law explains why a passenger in a car continues to move when a car rapidly stops. The seatbelt is the force that holds the passenger in the car because the seatbelt is attached the car. If the passenger is not wearing a seatbelt the windshield may be the force that holds the passenger in the car, if the passenger breaks the windshield the asphalt will be the unbalanced force stopping the passenger. Newton’s first law explains why a passenger in a car continues to move when a car rapidly stops. The seatbelt is the force that holds the passenger in the car because the seatbelt is attached the car. If the passenger is not wearing a seatbelt the windshield may be the force that holds the passenger in the car, if the passenger breaks the windshield the asphalt will be the unbalanced force stopping the passenger.

Mass is measured in kilograms (kg). A small car may have a mass of 1,000 kg and a bicycle may have a mass of 10 kg. Which object is easier to start and stop? Mass is measured in kilograms (kg). A small car may have a mass of 1,000 kg and a bicycle may have a mass of 10 kg. Which object is easier to start and stop? Mass has a direct correlation with inertia Mass has a direct correlation with inertia The greater the mass the greater the inertia The greater the mass the greater the inertia The smaller the mass the smaller the inertia The smaller the mass the smaller the inertia * 1 kg = 1,000 g

Force is a push or a pull Force is a push or a pull Unbalanced force creates, changes or stops acceleration Unbalanced force creates, changes or stops acceleration Balanced forces do not change acceleration Balanced forces do not change acceleration Inertia is the resistance of an object to change Inertia is the resistance of an object to change Coin and cup demo

Anderson, M. et all (2012) Physical Science. McGraw-Hill: Columbus Anderson, M. et all (2012) Physical Science. McGraw-Hill: Columbus Frank, D.V et al (2001). Physical Science. Prentice Hall: New Jersey Frank, D.V et al (2001). Physical Science. Prentice Hall: New Jersey