Science Teaching Junkie Science Teaching Junkie

Transcription

1 Science Teaching Junkie

2 Thank you for your purchase. I hope you enjoy the Force and Motion for Interactive Science Notebooks! It includes 30 pages of foldables and flippables for student notebooks. Many pages also include a Teacher Answer Key. Please don t hesitate to contact me with any questions, comments or concerns. My shayna_rose@yahoo.com Science Teaching Junkie blog: Teachers Pay Teachers Store: Junkie

3 Admit and Exit Tickets things I learned things that were surprising question I still have

4 Force What is force? How is it measured? What 2 things does every force have? How can forces affect an object? Describe and give examples of: Balanced Forces Unbalanced Forces

5 Distance Distance Distance Distance Motion Represented Graphically Time No movement - At rest Time Constant speed Time Positive Acceleration Time Negative Acceleration Show how the motion is graphically represented (include units for both the distance and the time). On the back, give a real-world example of the motion and add any additional description (optional).

6 Force Net Force = Net Force = Net Force = Net Force = Net Force = Net Force = Net Force = 2N 5N COMBINING FORCES Determine the net force (size and direction) 5N 4N 3N 6N 3N 3N 3N 4N 4N 3N 5N 6N

7 Newton s Laws Newton s Laws of Motion First Law of Motion - Law of Inertia Second Law of Motion - Law of Force & Acceleration Third Law of Motion - Law of Action Reaction Cut out each rectangle. Stack on top of each other, slightly raising each one so that the law title shows. Glue in notebook.

8 Inertia Example Definition/ Description Inertia Illustration Non-Example The center square may be cut out completely and glued into the notebook to become the center of the template; or only 3 sides of the square may be cut, leaving it attached to one of the tabs.

9 You are driving down the road at 50 miles per hour. What forces are present? What has inertia? Law of Inertia Inertia What will happen? Why? What is the relationship between inertia and mass? Explain Newton s First Law in terms of why we wear seatbelts. You suddenly slam on the brakes to avoid a deer. Explain what happens to your body and why. Why do we wear seatbelts?

10 How well do I understand Newton s Second Law: Law of Force and Acceleration? Newton's Second Law of Motion: Law of Force and Acceleration A toy car pulled by a little boy has an acceleration of 3.0 m/s 2. What is the mass of the car if the net force on the car is 10 N? Show your work. Why is it harder to throw a bowling ball than it is to throw a baseball? Second Law of Motion Explain the relationship between force, mass and acceleration.

11 Describe the force pairs present when a rocket launches. Newton's Third Law of Motion: Law of Action-Reaction Action

12 Newton's Third Law of Motion: Law of Action-Reaction What do I understand about Newton's Third Law of Motion: Law of Action Reaction? Question 1 How does the third law help a swimmer swim through the water?

13 Newton's Third Law of Motion: Law of Action-Reaction Question 2 Describe the action and reaction forces at work when a volleyball player serves the ball. Question 3 If force pairs are always opposite, explain why they don t always cancel each other out.

14 Newton's Third Law of Motion: Law of Action-Reaction Question 4 There are many forces that we can t see acting on objects all the time. List as many invisible forces as you can.

15 Newton at Work in Sports Newton s Laws at Work Newton at Work in Sports Describe a play in your favorite sport. First Law Second Law at Work at Work Third Law at Work Newton at Work in Sports Newton at Work in Sports

16 Define, give examples & units for each Speed, Velocity, & Acceleration Speed Velocity Acceleration

17 Physical Science Equations Equation in symbols: F = m a Equation in words: SI Units of Measurement: meters per second, m/s (speed) meters, m (distance) seconds, s (time) SI Units of Measurement: joules, J (work) newtons, N (force) meters, m (distance) Equation in symbols: W = m g Equation in words:

18 Calculating Work, Force & Distance Imagine that you push a large box with a force of 10 Newtons, but because the box is so heavy, it doesn t budge. How much work have you done? Imagine that you push that same box with a force of 30 Newtons over a distance of 2 meters. How much work have you done? If Arnold lifts the weight bar 5 meters and does 60 joules of work, how much does the bar weigh? (Hint: The weight of an object is considered to be a force.) A force of 100 Newtons was necessary to lift a rock. A total of 150 joules of work was done. How far was the rock lifted? Calculating Work Work

19 Force - KEY A force is a push or pull. It is measured in units called Newtons (N). Every force has a magnitude (strength) and a direction. Forces can set a stationary object in motion, change a moving object s speed and/or direction, or act on a stationary object by changing it s shape. (like when you sit on an inner tube and the sides bulge out). Describe and give examples of: Balanced Forces Unbalanced Forces These forces cause no change in motion. And object that is moving will maintain its speed and direction if balanced forces are acting on it. An object that is not moving will stay motionless. Ex: A book on a table will stay at rest. These forces cause a change in the motion of an object. A motionless object will begin to move, while an object that is already moving will change its speed and/or direction Ex: A ball rolling on the ground will come to rest because friction between the ball and the ground creates an unbalanced force.

20 Distance Distance Distance Distance Motion Represented Graphically Time No movement - At rest Time Constant speed Time Positive Acceleration Time Negative Acceleration Show how the motion is graphically represented (include units for both the distance and the time). On the back, give a real-world example of the motion and add any additional description (optional).

21 Force Net Force = 9N; up Net Force = 9N; right Net Force = 0N; no mo- Net Force = 3N; right Net Force = 1N; right Net Force = 8N; right Net Force = 0N; no mo- 2N 5N COMBINING FORCES Determine the net force (size and direction) 5N 4N 3N 6N 3N 3N 3N 4N 4N 3N 5N 6N

22 Newton s Laws Newton s Laws of Motion An object at rest will stay at rest and an object in motion will stay in motion at a constant velocity (same speed and same direction) unless acted upon by an unbalanced (outside) force. First Law of Motion - Law of Inertia The acceleration of an object by a force is inversely proportional to the mass of the object and directly proportional to the force. F= ma Second Law of Motion - Law of Force & Acceleration For every action, there is an equal but opposite reaction. Forces come in pairs. Third Law of Motion - Law of Action Reaction Cut out each rectangle. Stack on top of each other, slightly raising each one so that the law title shows. Glue in notebook.

23 Inertia It is harder to push an elephant than to push a ladybug. The tendency of an object to resist a change in motion. The greater an object s mass, the greater its inertia and the larger the force needed to overcome the inertia. Inertia Accept all reasonable responses The center square may be cut out completely and glued into the notebook to become the center of the template; or only 3 sides of the square may be cut, leaving it attached to one of the tabs.

24 Everything in the car, including the driver, are traveling at a speed of 50 mph. The tires are pushing back on the road, while the road pushes the tires forward. Law of Inertia Inertia What will happen? The card will fly away and the coin will fall into the cup. Why? This will happen because Newton s First Law states that an object at rest will remain at rest, unless an unbalanced force acts upon it. In this case, everything is at rest until your finger flicks the card. If the force is great enough, only the card will go flying (and not the coin) because the card is the only thing that received the force. Note: If the force applied to the card is not great enough, the friction between the card and the coin will be greater causing both objects to move together. The greater the mass, the greater the inertia. Explain Newton s First Law in terms of why we wear seatbelts. When you slam on the brakes, your body and everything in the car continues to travel straight down the road at a speed of 50 mph. This is why we wear seatbelts. The seatbelt is intended to stop the forwad motion of your body, so that you don t go flying through the windshield.

25 How well do I understand Newton s Second Law: Law of Force and Acceleration? Newton's Second Law of Motion: Law of Force and Acceleration m = F a m = 10N 3.0 m/s 2 m = 3.3 kg Teacher note: Fold this flap down Because a bowling ball has more mass, it also has more inertia. Therefore, it takes more force to overcome the inertia of the bowling ball than the baseball. A given force exerted on a small mass produces a greater acceleration than the same force exerted on a large mass. The acceleration of an object is inversely proportional to the mass of the object meaning that as one increases, the other decreases by the same ratio. (Ex: The greater the mass of an object, the less acceleration it will have (assuming the force remains the same). The acceleration of an object is directly proportional to the force which means that as one increases, the other increases. (ex: The harder you throw a ball, the greater the acceleration.) Second Law of Motion

26 Describe the force pairs present when a rocket launches. Newton's Third Law of Motion: Law of Action-Reaction the combustion products from the burning propellants accelerate rapidly out of the engine downwards (Rocket pushes gases downward.) The rocket, in turn, is forced skyward and slowly accelerates. (Gases push the rocket upward.) Action

27 Newton's Third Law of Motion: Law of Action-Reaction What do I understand about Newton's Third Law of Motion: Law of Action Reaction? Question 1 How does the third law help a swimmer swim through the water? As the swimmer pushes the water backwards, the water pushes the swimmer forwards.

28 Newton's Third Law of Motion: Law of Action-Reaction Question 2 Describe the action and reaction forces at work when a volleyball player serves the ball. As the player s hand pushes forward on the ball, the ball pushes back on her hand. Question 3 If force pairs are always opposite, explain why they don t always cancel each other out. The reason is that action and reaction forces act on different objects. For example, think about throwing a ball. When you throw a ball, you apply the action force to the ball, creating the ball s acceleration. The reaction is the ball pushing back against your hand. The action acts on the ball and the reaction acts on your hand. The forces do not cancel because they act on different objects. You can only cancel forces if they act on the same object

29 Newton's Third Law of Motion: Law of Action-Reaction Question 4 There are many forces that we can t see acting on objects all the time. List as many invisible forces as you can. Gravity, friction, air resistance, magnetism

30 Define, give examples & units for each Speed, Velocity, & Acceleration Distance traveled by an object in a given amount of time An object s speed and direction at a given instant (ex: the car is traveling 50 m/s north.) Change in an object s speed or direction (its velocity) over time. If an object is speeding up, slowing down, or changing direction, it is accelerating. Scientists refer to speeding up as positive acceleration and slowing down as negative acceleration.

31 Physical Science Equations Equation in symbols: F = m a Equation in words: Force equals mass times acceleration SI Units of Measurement: Newtons, N (force) Kilograms, kg (mass) meters per second squared, m/s 2 (acceleration) Equation in symbols: s = d t Equation in words: Speed equals distance divided by time SI Units of Measurement: meters per second, m/s (speed) meters, m (distance) seconds, s (time) Equation in symbols: W = F d Equation in words: Work equals force times distance SI Units of Measurement: joules, J (work) newtons, N (force) meters, m (distance) Equation in symbols: W = m g Equation in words: Weight equals mass times acceleration due to gravity SI Units of Measurement: Newtons, N (weight) Kilograms, kg (mass) meters per second squared, m/s 2 (acceleration)

32 Calculating Work, Force & Distance You haven t done any work (0 joules). In order for work to be done, a force must be applied to an object and the object must move a distance. W = F d W = 30 N 2 m W = 60 Joules F = W d F = 60J 5 m F = 12 N or 2.7 pounds (There are N in one pound) D = W f D = 150 J 100 N D = 15,000 m Calculating Work Work is accomplished when force is applied to an object and the object moves a distance. Work is measured in newtonmeters, more commonly called joules (J). Work