This document discusses the difference between mass and weight. It explains that mass is a measure of the amount of matter in an object and stays constant wherever the object goes, while weight is the force exerted on an object by gravity and depends on the gravitational field. It provides examples of how the weight of an object would change on different celestial bodies due to variations in gravity. The document also describes how to measure weight using a spring scale and includes questions at different levels about mass, weight, and gravity.

1. 5.2 A weight problem 06 January 2011How many forces do you know?How do you measure a force?How much do you weigh?

2. AimsRecord measurements of mass and weight in appropriate units. [Level 4]Recognise that some forces act at a distance and others are ‘contact’ forces. [Level 4]Explain the difference between mass and weight. [Level 5]Explain how weight is caused by gravity acting on a mass. [Level 6]

3. KeywordsContact forceFrictionGravityKilogramMagnetismMassNewtonWeight

7. Rmg

8. Contact VS non-contactUpthrustMagnetismFrictionAir resistanceWeight

9. Weight and massIf you buy a can of coke it has a mass – its made of stuff. If you take it to the Moon it still is made of the same stuff, its mass doesn’t changeThe weight of the coke depends on the gravity of the objects it is near to. The Earth has more gravity than the Moon so on the Moon it would have less weightYou can tell they are not the same as they have different units!

10. Weight VS Mass

11. Weight VS Mass

12. Plotting mass against weight

13. Plotting mass against weight

14. Converting mass into weightOn earth you multiply the mass in kilograms by 10 N/kgOn the Moon you multiply by 1.6 N/kgOn Jupiter you multiply by 26 N/kg

15. Measuring weightYou use a spring balance or force meter or newton meter to measure weightIt simply measures the stretch of a spring that has been calibrated in the factory – big stretch is a big force

17. 5.2 A weight problemQuestions(Level 3)Copy and complete the sentences below using these words: weight mass newtons kilogramsThe _______ of an object is constant and depends on the amount of matter it has. Gravity gives an object its _______. Mass is measured in _______. Weight is a force and is measured in _______.If you went to the Moon, how would your weight and mass change?How do you think the Sun’s gravity compares with the Earth’s? Explain your answer.(Level 3)(Level 4)1 of 2

18. 5.2 A weight problemQuestions(Level 5)Rank these objects in terms of the amount of gravity they have: Earth, Sun, pencil sharpener, Moon, Jupiter. Michelle says ‘If you go to the Moon, you’ll be slimmer because you lose weight’. Do you think she is right or wrong? Explain your answer.A rocket travels from the Moon to the Earth. Describe how its weight will change during the journey.Why is it important that a rocket has as little mass as possible? (Level 6)(Level 7)(Level 7)2 of 2