What to do… Open your note packet to page 32 Answer the following in your “Think About It” How do you think mass will affect an objects acceleration? Use your own words.

Newton’s Second Law Chapter 20, Section 2 SPI: 11.4- Identify and explain how Newton’s laws of motion relate to the movement of objects.

Newton’s 2nd Law of Motion The acceleration of an object is equal to the net force exerted on the object divided by the object’s mass. Force = Acceleration = The acceleration due to gravity on earth = Mass x Acceleration Force Mass 9.8 m/s2

Three Forms of Newton’s 2nd Law If you want to find… And you know… Then the formula you would use is… Acceleration (a) Net Force (F) Mass (m) Net Force (F) and mass (m) Acceleration (a) and mass (m) Net Force (F) and acceleration (a)

Units for solving for Newton’s 2nd Law Identify the information you are given Look at the units Unit for Force – Newton (N) Remember: Weight is a force due to gravity If the problem asks you to solve for weight you need to identify the acceleration due to gravity for you given location Unit for Acceleration – m/s2 Unit for Mass – kg or g

Units for solving for Newton’s 2nd Law Remember: Weight is a force due to gravity If the problem asks you to solve for weight you need to identify the acceleration due to gravity for you given location Unit for Acceleration – m/s2 Unit for Mass – kg or g

An object at REST Balanced Force The force exerted by the is to Unbalanced Force The force exerted by gravity is than air resistance. HAND EQUAL GREATER THE FORCE OF GRAVITY

An object in MOTION Increase Speed Decrease Speed Change Direction Unbalanced forces cause objects to Accelerate Increase Speed Decrease Speed Change Direction

Part I: Acceleration Depends on Mass Acceleration as its mass decreases increases Acceleration as mass increases decreases Acceleration and mass are inversely related Example: You are pushing a shopping cart at the grocery store. At the beginning of your shopping trip, you exert a small force on the cart to accelerate it. (smaller mass = greater acceleration) Exert the same amount of force when the cart is full and the cart will not accelerate as much. (greater mass = smaller acceleration)

Part II: Acceleration Depends on Force Acceleration as the force on it increases increases Acceleration as the force on it decreases decreases Acceleration and force are directly related Example: When pushing the full shopping cart, if you push harder (greater force), the cart will move faster. If you push the full shopping cart with less force, the cart will move slower. **The acceleration is always in the as the force applied. The shopping cart moved forward because the push was in a forward direction same direction

We know that objects with different masses accelerate to the ground However, because of the 2nd Law we know that they don’t hit the ground with the same at the same rate. force. F = ma 9.8 N = 1 kg x 9.8 m/s/s F = ma 98 N = 10 kg x 9.8 m/s/s

DO!! Examine this picture: Explain the Second Law of Motion using this picture as an example. Be sure to identify all forces. The acceleration of the table depends on how heavy or light it is AND how much force the man is putting on it

Keys to Understanding At LEAST 5 complete sentences Summarize the main points of the lesson Describe in detail the important ideas Write about concepts you want to remember This should be helpful to YOU!