Difference between revisions of "GCSE Physics Required Practical: Investigating Hooke's Law"
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==Key Stage 4== | ==Key Stage 4== | ||
| + | {{#ev:youtube|https://www.youtube.com/watch?v=QQCJeAqBumE}} | ||
===Meaning=== | ===Meaning=== | ||
Investigate the relationship between the [[extension]] of a [[Coil Spring|spring]] and the [[force]] applied to that [[Coil Spring|spring]]. | Investigate the relationship between the [[extension]] of a [[Coil Spring|spring]] and the [[force]] applied to that [[Coil Spring|spring]]. | ||
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#Attach a known [[weight]] (approximately 1N) to the [[Coil Spring|spring]]. | #Attach a known [[weight]] (approximately 1N) to the [[Coil Spring|spring]]. | ||
#[[Measure]] the new length of the [[Coil Spring|spring]]. | #[[Measure]] the new length of the [[Coil Spring|spring]]. | ||
| − | #Calculate the [[extension]] of the [[Coil Spring|spring]] by | + | #Calculate the [[extension]] of the [[Coil Spring|spring]] by subtracting the original length from the new length of the [[Coil Spring|spring]]. |
#Repeat steps 2-4 up to around 6N. | #Repeat steps 2-4 up to around 6N. | ||
| − | #Plot a [[graph]] with the [[force]] of [[weight]] on the [[y-axis]] and the [[extension]] on the [[x-axis]]. The [[gradient]] of | + | #Plot a [[Scatter Graph|scatter graph]] with the [[force]] of [[weight]] on the [[y-axis]] and the [[extension]] on the [[x-axis]]. The [[gradient]] of [[Line of Best Fit|line of best fit]] will be the [[Spring Constant|spring constant]] of the [[Coil Spring|coil spring]]. |
====Improving [[Accuracy]]==== | ====Improving [[Accuracy]]==== | ||
| − | : Calculate the [[weight]] added by [[measure|measuring]] its [[mass]] each time and using the equation <math>W=mg</math> with <math>g=9.8</math>. This will give a more [[accuracy|accurate]] knowledge of the [[weight]] rather than relying on the number printed on the [[weight]]s. | + | : Calculate the [[weight]] added by [[measure|measuring]] its [[mass]] using an [[Electronic Balance|electronic balance]] on a flat, level surface each time and using the equation <math>W=mg</math> with <math>g=9.8</math>. This will give a more [[accuracy|accurate]] knowledge of the [[weight]] rather than relying on the number printed on the [[weight]]s. |
| − | : Add a [[Fiduciary Marker|fiduciary marker]] to the bottom of the [[Coil Spring|coil spring]] to prevent any [[error]] caused by not [[read]]ing the [[ruler]] from | + | : Add a [[Fiduciary Marker|fiduciary marker]] to the bottom of the [[Coil Spring|coil spring]] to prevent any [[error]] caused by not [[read]]ing the [[ruler]] from eye level. |
: Ensure the [[Coil Spring|spring]] is not moving when taking [[measure]]ments of it's length. | : Ensure the [[Coil Spring|spring]] is not moving when taking [[measure]]ments of it's length. | ||
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====Improving [[Precision]]==== | ====Improving [[Precision]]==== | ||
| − | : | + | : Add a [[Fiduciary Marker|fiduciary marker]] with a fine point to the bottom of the [[Coil Spring|coil spring]] to give [[precise]] [[read]]ings of the length of the [[Coil Spring|coil spring]]. This makes it easier to see the [[length]] of the [[Coil Spring|coil spring]] by reducing the [[Random Error|random error]] caused by not being exactly at eye level for each [[repeat]]ed [[result]]. |
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Latest revision as of 11:33, 13 April 2019
Contents
Key Stage 4
Meaning
Investigate the relationship between the extension of a spring and the force applied to that spring.
Experiment
Variables
- Independent Variable: The force applied to the spring.
- Dependent Variable: The extension of the spring.
- Control Variables: The spring being used.
Method
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A diagram of the apparatus used to investigate the effect of a force on the extension of a spring. |
- Set up the equipment as shown in the diagram.
- Measure the original length of the spring using a ruler.
- Attach a known weight (approximately 1N) to the spring.
- Measure the new length of the spring.
- Calculate the extension of the spring by subtracting the original length from the new length of the spring.
- Repeat steps 2-4 up to around 6N.
- Plot a scatter graph with the force of weight on the y-axis and the extension on the x-axis. The gradient of line of best fit will be the spring constant of the coil spring.
Improving Accuracy
- Calculate the weight added by measuring its mass using an electronic balance on a flat, level surface each time and using the equation \(W=mg\) with \(g=9.8\). This will give a more accurate knowledge of the weight rather than relying on the number printed on the weights.
- Add a fiduciary marker to the bottom of the coil spring to prevent any error caused by not reading the ruler from eye level.
- Ensure the spring is not moving when taking measurements of it's length.
 |
A fiduciary marker can be added to improve accuracy and precision of the length measurements. |
Improving Precision
- Add a fiduciary marker with a fine point to the bottom of the coil spring to give precise readings of the length of the coil spring. This makes it easier to see the length of the coil spring by reducing the random error caused by not being exactly at eye level for each repeated result.