Forces Notes Title FORCES NOTES Objective Identify and
Forces Notes Title: FORCES NOTES Objective: Identify and describe the changes in position, direction, and speed of an object when acted upon by unbalanced forces.
THINK… 1. 2. What would happen if both people pushed in the same direction? Why? What happens when the people are pulling in the opposite direction? Why?
Review: What Is Mass? Mass is the amount of matter in an object. We measure mass with a triple beam balance. The unit of measurement for mass is the gram (g).
What Is Force? Force is a push or pull that one object exerts on another. A force has both size and direction. Fkick Fgravity
What are some common forces? Some common examples of force are: §Gravitational Force (Gravity) §Weight §Friction §Applied force § Balanced Force § Unbalanced Force
How do we measure Force? • Force is the mass of an object multiplied by the object’s acceleration. We can calculate force using the formula F=ma • We use a Spring Scale to measure force. • The unit of measurement force is the Newton (N)
What is Weight Force? • Weight Force is the mass of an object multiplied by the acceleration due to gravity. We calculate it the same way as any other force, but with a special acceleration number that is always the same. • The acceleration due to gravity is always 9. 8 m/s 2 and we represent this very special acceleration with the letter g. • We can calculate weight force using the formula Fw=mg. • We use a Scale to measure weight force. • The unit of measurement force is the Newton (N)
Let’s Review 1. What is mass? 2. What tool do we use to measure mass? 3. What is the unit of measurement for mass? 4. What is weight? 5. What tool do we use to measure weight? 6. What is the unit of measurement for weight?
What are some common forces? Gravitational Force (Gravity) – The force of attraction between objects that is due to their masses. You feel the force of gravity pulling you to Earth when you jump up and down. Weight - a measure of gravitational force on an object. • We measure weight (force) with • Unit = Newton a Spring Scale.
What are some common forces? Friction – a force that opposes motion at a contact point between two surfaces. • Air resistance is a type of friction • Friction makes objects slow down or stop moving
What are some common forces? Applied force – a push or pull on an object by a person or another object.
Net Force Net force is the combined effect of all forces acting on an object.
Balanced Forces • Balanced forces are forces acting on an object that are opposite in direction and equal in size • There is no change in position, direction of motion, or speed of an object when all of the forces are balanced • Balanced forces make an object sit still or keep moving at a constant speed
Unbalanced forces • Unbalanced Forces are opposing forces that are not equal • Unbalanced forces cause change in position, direction of motion and speed of an object • Unbalanced forces make objects speed up, slow down, or change direction
1. What are the different forces acting on the figure skaters? 2. In what directions are the forces acting? 3. Are the forces balanced or unbalanced? How do you know?
Balanced and Unbalanced Forces Module http: //www. engineeringinteract. org/resources/parkworldplot/ flash/concepts/balancedandun. htm
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