1. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. Today’s Lesson Understand how scientists make use of last week’s experiment to measure forces Learn how to safely use a newton meter. Understand the difference between mass and weight.

2. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. Forces… Forces make things change the way they are moving – faster, slower, change direction or make the object deform: stretch, skew or deform

3. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. Stretching Springs

4. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. Why did the spring stretch?

5. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved.

6. Conclusion The bigger the weight added to the spring the more it stretched. Each newton of force that pulled at the spring made it extend by the same amount – that is why we got a straight line graph.

7. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. If a spring stretches by 17 cm what force did we apply?

8. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved.

9. A spring stretches proportionally to the force tugging at it. Newton meters (or force meters) use this fact to measure force.

10. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. Using a newton meter or force meter Zero errors Before you add the weight to the meter you must check that it is reading zero. Hold the meter vertically Hold the meter at eye level Safety! Don't hold heavy objects over your foot... or anyone else’s!

11. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. What is matter?

12. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. States of matter There are three states of matter: solid, liquid and gas - all of these contain atoms and/or molecules that make up the mass of the object.

13. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. What is mass?

14. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. Mass is the quantity of matter which a body contains. This is the same wherever the body is. It is measured in kg. Mass Always Stays the Same!!

15. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. What is weight?

16. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. Masses get pulled or tugged at by a force called gravity. That tug is called the weight. Weight: Experienced In Gravity's Hold or Tug

17. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. The Earth pulls at each newton of mass in an object on its surface with a force of 10N. We say that the gravitational field strength of Earth is 10N/kg a pull of 10N on each kilogram of mass.

18. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. Suit up! Because in this lesson you are going to: Travel around the solar system! Weigh a mass of 1 kilogram in various locations. Work out where you are from the weight of the mass.

19. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. Activity Worksheet

20. Garfield Graphics included with kind permission from PAWS Inc. All Rights Reserved. W eight: E xperienced I n G ravity's H old or T ug