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

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

Daily Reflection • Prompt: Write 3 facts about momentum

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

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.

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.

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

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

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

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

Conservation of Momentum

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

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

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

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

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

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