1. What is your objective for today? Describe what a force is and give an example Objective 1 vocabulary: forcemassweight Newtons atomprecision newton spring scale

3. Questions to discuss What does it mean forces `always act in a straight line`? Why can‘t a wavy line represent one force? Identify all of the forces in the illustration: A force is any push or pull motion that always acts in a straight line Forces are measured in Newtons. The higher the number of Newtons the stronger the force is. Which force in the illustration would you measure the highest and the lowest Newtons?

5. Mass is a measure of how much stuff or matter something is made of. Mass does not change with location Weight changes with location because the force of gravity changes. http://www.youtube.com/watch?v=xfGll1REu2A

6. Mass is measured using a top pan balance or a scale. Mass is measured in kilograms or grams. Weight is measured using a Newton spring scale and is measured in Newtons because weight is a force. Precision is how close to a true measurement an instrument can make. Uses*

7. 1kg of mass on earth pushes down on the Earth with a force of 10N 100g of mass on the Earth pushes down on the Earth with a force of 1N 32kg pushes down on the earth with a force of _______Newtons 712g pushes down on the earth with a force of _______Newtons

8. Calculate the forces 32kg = 32 x 10 = 320N 712g = 712/100 = 7.12N

9. Measure the mass of an object Measure and calculate the force produced ObjectMass Force -estimate using 1kg = 10 N & 100g = 1N Force measured using spring scale 1. 2. 3. you xxxxxxxxxxxxxxxxx 4. 5.

10. Activity questions 1. Was there a difference in the amount of force estimated and the force measured using the Newton spring scale? Why? 2. What was the relationship between an object’s mass and its force? 3. What was the precision of the Newton spring scales?