3 G8 Science Q1-Week 1 of 2Law of Acceleration.pptx

science 8

1. Law of Inertia Law of Acceleration Law of Interaction PREPARED BY : Teacher Marianne

2. Learning Objectives I can state Newton’s Laws of Motion. I can apply Newton’s Laws of Motion to real life situations. I can describe momentum of different objects and how it affects motion. I can explain the relationship between inertia and mass.

3. Newton ’ s Laws of Motion

4. REVIEW 1. Sir Isaac Newton 2. An object in motion tends to stay in motion and an object at rest tends to stay at rest unless acted upon by an unbalanced force. Inertia is an objects resistance to a change in its motion (even if it isn’t moving at all!) Inertia is caused because objects have mass The more mass an object has, the more inertia!

5. Newton’s Second Law (F = ma) Force equals mass times acceleration. F = ma Acceleration : a measurement of how quickly an object is changing speed.

6. VOCABULARY 1. Force = mass x acceleration F=m x a 2. Force- a push or pull , all forces have size and direction 3. Mass - the amount of matter an object is made of 4. Acceleration -the rate at which velocity changes; and object accelerates if its speed changes, if its direction changes and if both speed and direction changes

7. More Force = more Acceleration More Mass = more Force needed = less acceleration Newton’s Second Law of Motion says: “To move a mass, you need a force!” Also known as F=ma I am so smart … The greater the mass = greater inertia = more force needed! Acceleration is directly proportional to Force while acceleration is inversely proportional to mass

8. Look at the pictures on the right. Which vehicle do you think would require a greater force to push? Why do you think this? Using the equation, solve for the amount of force.

9. Newton’s Second Law (F = ma)

10. Newton’s Second Law (F = ma)

11. Newton’s Second Law (F = ma)

12. PRACTICE TEST How fast will an 800kg car accelerate if it is pushed with 4000N of force? How fast will a 0.15kg hockey puck accelerate if it is hit with 1.2 N of force?

13. How fast will an 800kg car accelerate if it is pushed with 4000N of force?

14. How fast will a 0.15kg hockey puck accelerate if it is hit with 1.2 N of force

15. A 1000.0 kg truck is traveling at an acceleration of 4.5000 m/s2, East. Find the net force needed to accelerate the truck.

16. A boy rolls a 200 g baseball horizontally on the floor with a net force of 2 N to the right. What is the acceleration of the baseball?

17. A box is pushed with an applied force of 20 N parallel to the floor. It accelerated at 1.50 m/s2 to the right. Neglecting friction, what is the mass of the box?