Lesson Starter What is a force? Describe how a balanced force affects a) a moving object b) a stationary object Describe how an unbalanced force affects:

To learn how to measure a force using a spring Learning Intention To learn how to measure a force using a spring

Discuss.. Why is bottle B`s spring stretched more than bottle A`s spring? What is pulling down the two bottles?

Investigate Is there a link between the mass hanging from the spring and the length of its stretch? 1. Measure the length of the unstretched spring. 2. Either hold the spring or use a clamp stand to hold it. 3. Start by hanging the carrier on the spring. (The carrier has a mass of 100g) 4. Measure, with a ruler, the length of the stretch of the spring. Don’t forget to take away the length of the unstretched spring!

What are you investigating? Aim What are you investigating? To find out if there is a link between the mass hanging on a spring and its stretch

Method Write down step by step instructions as to how you carried out your experiment. Draw a labelled diagram of how your experiment was set up

Results

Stretchy Springs Lab Report Aim Method (instructions + diagram) Results (copy the table) Graph (on graph paper) Conclusion

Plotting Line Graphs: Rules Always use a ruler Always label your axis Always use correct units Always use an appropriate scale Always plot your points accurately

Conclusion What did you find out? What was the link between the mass hanging on a spring and its stretch

Use your graph to find out the mass of objects Experiment Use your graph to find out the mass of objects

Gravity Force of attraction Pull- keep you on the ground Every object in the universe that has mass exerts a gravitational pull or force, on every other mass. The size of the pull depends on the masses of the objects. Weight is a force caused by gravity. Weight of an object is the gravitational force between the object and the Earth.

Copy and complete An object attached to the end of a spring will _________ it. The bigger the mass of the __________ the ___________ the spring stretches. The force that pulls on the object is called the force of _____________ This special force gives the object ___________ Weight is name given to the force of gravity _________ downward on the object