2/24 & 2/25- 8 th Grade Agenda

1. 2/24 & 2/25- 8th Grade Agenda Learning Objective: Learn about Rockets & Satellites Collect HW: Reading & Notetaking p.185 – 187 Science Fair Presentations Textbook Reading p. 403 HW: Reading & Notetaking p.188 Reminder: Chap 9 & 10 Test on 2/26 & 2/27

2. Daily Reflection • Prompt: Write 3 facts about momentum

3. Reflection • Prompt: Write 5 facts that you learned during the Science Fair Presentations

4. Write the following in your notesNewton’s First Law of Motion: Law of Inertia • Once moving at a steady speed and in a straight line the object will continue moving at a steady speed in a straight line. • Once Standing still the object will continue to stay still until acted upon.

5. Write the following in your notesNewton’s Second Law of Motion:F = mass X acceleration • Object accelerates in the direction that you push it. • If you push twice as hard, the object will accelerate twice as much. • If the object gains twice that mass it will accelerate half as much.

6. Compute the following in your notes • Force = Mass X Acceleration • Kg X m/s2 = newtons • Force = 70 kg X 5 m/s2 = • Force = 50 kg X 4 m/s2 = • A 4000 kg car is accelerating at 5 m/s2. What is the net force of the acceleration? 350 newtons 200 newtons 20,000 newtons

7. Compute the following in your notes • Weight = Mass X acceleration due to gravity • Kg X m/s2 = newtons • On earth, acceleration due to gravity is 9.8 m/s2 • Weight = 100 kg X 9.8 m/s2 = • Weight = 10 kg X 9.8 m/s2 = • What is the weight of a car in newtons which has a mass of 1000 kg? 980 newtons 98 newtons 9800 newtons

8. Compute the following in your notes • Momentum = Mass X Velocity • Momentum = 20 kg X 40 m/s = • Momentum = 3 kg X 300 m/s= • A baseball travels at 8 m/s, while a basketball moves at 3 m/s. The mass of the baseball is .2 kg and the mass of the basketball is .6 kg. Which has greater momentum? 800 kg m/s 900 kg m/s Baseball = .2 kg X 8 m/s = 1.6 kg m/s Basketball = .6 kg X 3 m/s = 1.8 kg m/s

9. Newton’s Third Law of Motion: • If one object exerts a force on another object, then the second object exerts a force of equal magnitude in the o________ direction on the first object • If you push on it, it pushes on you pposite

10. Conservation of Momentum

11. Conservation of Momentum

12. Conservation of Momentum

13. Conservation of Momentum

14. Conservation of Momentum

15. Conservation of Momentum

16. Law of Conservation of Momentum • The total momentum of any group of objects remain the s_____ unless outside f______ act on the object • Friction is an example of an outside force ame orce

17. Gravity is responsible for orbit of planets and satellites • http://galileoandeinstein.physics.virginia.edu/more_stuff/Applets/newt/newtmtn.html • http://spaceplace.nasa.gov/en/kids/orbits1.shtml

18. What would happen if we fired a cannon ball with lot more gun powder?

19. Why doesn’t a satellite in orbit around Earth fall into Earth? • It is continually falling. • Curvature of the Earth prevents it from falling to the ground

20. Objects in low earth orbit travels at 7900 m/s (16,000 km/hr)

21. Objects in low earth orbit travels at 7900 m/s (16,000 km/hr)