P5 - Investigating Springs Flashcards
NOTE: For investigating springs practical and the link between for and extension
Check page 206 and check the top right hand corner to see how to set up the apparatus ( equipment )
What is the apparatus needed for the investigating springs and link between force and extension practical?
- A spring ( or multiple to see variation of results)
- Fixed ruler
- Clamp
- Extra masses
- Tape to mark end of the spring
- Hanging masses
What does it mean during the practical if the extension of the spring increases than the previous masses?
You have gone past the springs limit of proportionality. If this happens, you may need smaller masses, or else you will not get enough measurements for your graph
State the steps needed to complete the investigating springs and the link between forces and extension PRACTICAL
1) Measure the natural length of the spring (when no load is applied) with a millimetre ruler clamped to the stand. Make sure you take the reading at eye level and add a marker (e.g. a thin strip of tape) to the bottorn of the spring to make the reading more accurate.
2) Add a mass to the spring and allow it to come to rest. Record the mass and measure the new length of the spring. The extension is the change in length.
3) Repeat this process until you have enough measurements (no fewer than 6).
4) Plot a force-extension graph of your results.
It will only start to curve if you exceed the limit of proportionality,but don’t worry if yours doesn’t (as long as you’ve got the straight line bit).
When plotting the graph for the investigating springs practical state what does it means if the results are straight or when they curve.
If the line of best fit is a straight line it means there is a linear relationship. However, when the line begins to bend, this means the relationship is now non-linear between the force and extension - the spring stretches more for each unit increase in force
Equation to find elastic potential energy/ ‘work’ done
Elastic potential energy (J) = 1/2 x Spring constant (N/m) x Extension^2 (m)
Ee = 1/2ke^2
What can the equation to find elastic potential energy store also find?
For elastic deformation, this formula can be used to calculate the energy stored in a spring’s elastic potential energy store. It’s also the energy fransferred to the spring as it’s deformed (or transferred by the spring as it returns to its original shape).
