1. Newton’s Second Law of Motion Review Homework Notes: Newton’s Second Law of Motion iMovie: 2 objects Homework: Practice Problems Newton’s Second Law of Motion

2. The blood in your head is moving downward as you descend. When the elevator stops the blood in your head continues to move downward because of its inertia.

3. The hammer is moving downward. When the hammer hits the hard surface the hammerhead continues to move downward because of its inertia.

4. The ketchup and the ketchup bottle are moving downward. When the ketchup bottle stops the ketchup continues to move downward because of its inertia.

5. Your body and head are at rest in a car. When another car crashes into you from behind your body and head want to remain at rest because of inertia. The headrest makes sure your head moves forward with your body.

6. You and the skateboard are moving forward. When the skateboard hits the curb your body continues to move forward because of its inertia.

7. The space probe Voyager is launched into space moving forward. No unbalanced force acts on the Voyager so it continues in motion because of its inertia.

8. Notes: Newton’s Second Law of Motion (copy in your notes) The acceleration of the object depends on the net force acting on the object and the mass of the object. If mass is constant, the more force you apply to an object the faster it will change its motion. It requires more net force to change the motion of objects with more mass.

9. Notes: Newton’s Second Law (copy in your notes) Newton’s Second Law can also be written as a mathematical formula. Force = mass x acceleration F = ma

10. F= mass x acceleration A person with a mass of 75 kg accelerates to the right at 2 m/s/s. When they crash into another person what is the force? 75kg x 2m/s/s = 150N

11. F=ma An 500 kg elephant is dropped from the balcony of the atrium. Calculate the force the elephant will exert on the floor when it hits the ground. 500kg x 9.81m/s/s = 4905N

12. Solving for Mass and Acceleration (copy in your notes) Mass = Force / Acceleration Acceleration = Force / Mass

13. Mass = Force / Acceleration A bike that was accelerating 3 m/s/s crashes into a wall with a force 60 N. What is the mass of the bike? 60N / 3m/s/s = 20kg

14. Acceleration = Force / Mass A 0.5 kg soccer ball is kicked with 2 N of force. What is its acceleration? 2N / 0.5kg = 4m/s/s

15. Lab: Newton’s Second Law of Motion Make a short iMovie that clearly labels the following events for two objects. One object should have a large mass and the other a small mass. Show how you found the mass of the object. Show your calculation for the Force with which gravity is pulling on the object. (Hint: you are on Earth) Show your object on a spring scale to see if our spring scales work. Clearly state if the spring scale is accurate or not. Show your calculation for the Force with which gravity would pull on your object on the moon (acceleration due to gravity on moon = 1.62m/s/s)

16. Homework: Practice Problems for Newton’s Second Law of Motion Complete questions 1-10 Show ALL of your work!