Difference between revisions of "Moment"
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|[[File:PivotLever.png|center|400px]] | |[[File:PivotLever.png|center|400px]] | ||
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| − | | style="height:20px; width:200px; text-align:center;" |Using '''moments''' an effort can be used to lift a load. If the [[pivot]] is closer to the load than the effort then the [[force]] of effort can be smaller than the load to lift the object. | + | | style="height:20px; width:200px; text-align:center;" |Using '''moments''' an effort can be used to lift a load. If the [[pivot]] is closer to the load than the effort then the [[force]] of effort can be smaller than the load to lift the [[object]]. |
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<math>M = 2.0Nm</math> | <math>M = 2.0Nm</math> | ||
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| + | |||
| + | ==Key Stage 4== | ||
| + | ===Meaning=== | ||
| + | A '''moment''' is the turning effect of a [[force]]. | ||
| + | |||
| + | ===About Moments=== | ||
| + | : When a [[force]] acts on an [[object]] with a [[pivot]] it becomes a turning force called a [[moment]]. | ||
| + | : A '''moment''' can be calculated by multiplying a [[force]] by the [[distance]] from a [[pivot]]. | ||
| + | : The [[unit]]s of a '''moment''' are [[Newton Metre]]s (Nm). | ||
| + | : '''Moments''' can be used to make [[Force Multiplier]]s using a [[pivot]] and [[lever]]. | ||
| + | : The longer the lever, the larger the [[moment]] that can be produced. | ||
| + | |||
| + | {| class="wikitable" | ||
| + | |- | ||
| + | |[[File:PivotLever.png|center|400px]] | ||
| + | |- | ||
| + | | style="height:20px; width:200px; text-align:center;" |Using '''moments''' an effort can be used to lift a load. If the [[pivot]] is closer to the load than the effort then the [[force]] of effort can be smaller than the load to lift the [[object]]. | ||
| + | |} | ||
| + | |||
| + | ===Equation=== | ||
| + | Moment = Force x Perpendicular distance from the pivot. | ||
| + | |||
| + | :<math>M = F \times d</math> | ||
| + | Where: | ||
| + | : M = [[Moment]] | ||
| + | : F = [[Force]] | ||
| + | : d = [[Perpendicular]] distance from the [[pivot]]. | ||
| + | |||
| + | ===Example Calculations=== | ||
| + | |||
{| class="wikitable" | {| class="wikitable" | ||
| − | | style="height:20px; width:200px; text-align:center;" | | + | | style="height:20px; width:200px; text-align:center;" |A hammer is used to pull out a nail from a wall. A 30N [[force]] of effort is applied at a [[perpendicular]] distance of 0.18m from the [[pivot]]. While the nail is 0.02m away from the pivot. Calculate the [[force]] applied to the nail at this point. |
| − | | style="height:20px; width:200px; text-align:center;" | | + | | style="height:20px; width:200px; text-align:center;" |A hammer is used to pull out a nail from a wall. A 30N [[force]] of effort is applied at a [[perpendicular]] distance of 19cm from the [[pivot]]. While the nail is 4cm away from the pivot. Calculate the [[force]] applied to the nail at this point. |
| − | | style="height:20px; width:200px; text-align:center;" | | + | | style="height:20px; width:200px; text-align:center;" |A hammer is used to pull out a nail from a wall. A 30N [[force]] of effort is applied at a [[perpendicular]] distance of 200mm from the [[pivot]]. While the nail is 60mm away from the pivot. Calculate the [[force]] applied to the nail at this point. |
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|[[File:MomentHammer1.png|center|200px]] | |[[File:MomentHammer1.png|center|200px]] | ||
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|[[File:MomentHammer3.png|center|200px]] | |[[File:MomentHammer3.png|center|200px]] | ||
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| − | | style="height:20px; width:200px; text-align:left;" | | + | | style="height:20px; width:200px; text-align:center;" |'''A 30N force of effort is applied at a [[perpendicular]] distance of 0.18m from the pivot. Calculate the Moment.''' |
| + | | style="height:20px; width:200px; text-align:center;" |'''A 30N force of effort is applied at a [[perpendicular]] distance of 19cm from the pivot. Calculate the Moment.''' | ||
| + | | style="height:20px; width:200px; text-align:center;" |'''A 30N force of effort is applied at a [[perpendicular]] distance of 200mm from the pivot. Calculate the Moment.''' | ||
| + | |- | ||
| + | | style="height:20px; width:200px; text-align:left;" |'''1. State the known quantities''' | ||
| + | Force = 30N | ||
| + | |||
| + | Perpendicular distance between effort and pivot = 0.18m | ||
| + | |||
| + | Perpendicular distance between effort and pivot = 0.02m | ||
| + | |||
| + | | style="height:20px; width:200px; text-align:left;" |'''1. State the known quantities''' | ||
| + | Force = 30N | ||
| + | |||
| + | Perpendicular distance between effort and pivot = 19cm = 0.19m | ||
| + | |||
| + | Perpendicular distance between effort and pivot = 4cm = 0.04m | ||
| + | |||
| + | | style="height:20px; width:200px; text-align:left;" |'''1. State the known quantities''' | ||
Force = 30N | Force = 30N | ||
| − | Perpendicular distance = 0. | + | Perpendicular distance between effort and pivot = 200mm = 0.200m |
| + | |||
| + | Perpendicular distance between effort and pivot = 60mm = 0.06m | ||
| + | |||
| + | | style="height:20px; width:200px; text-align:left;" |'''2. Find the [[moment]] caused by the [[effort]].''' | ||
<math>M = F \times d</math> | <math>M = F \times d</math> | ||
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<math>M = 5.4Nm</math> | <math>M = 5.4Nm</math> | ||
| − | | style="height:20px; width:200px; text-align:left;" | | + | | style="height:20px; width:200px; text-align:left;" |'''2. Find the [[moment]] caused by the [[effort]].''' |
Force = 30N | Force = 30N | ||
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<math>M = 5.7Nm</math> | <math>M = 5.7Nm</math> | ||
| − | | style="height:20px; width:200px; text-align:left;" | | + | | style="height:20px; width:200px; text-align:left;" |'''2. Find the [[moment]] caused by the [[effort]].''' |
Force = 30N | Force = 30N | ||
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<math>M = 6.0Nm</math> | <math>M = 6.0Nm</math> | ||
|- | |- | ||
| − | | style="height:20px; width:200px; text-align:center;" |''' | + | | style="height:20px; width:200px; text-align:center;" |'''3. Calculate the Force applied to the nail from the [[moment]]''' |
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| − | |||
| − | |||
| − | |||
Moment = 5.4Nm | Moment = 5.4Nm | ||
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<math>F = 270N</math> | <math>F = 270N</math> | ||
| − | | style="height:20px; width:200px; text-align: | + | | style="height:20px; width:200px; text-align:center;" |'''3. Calculate the Force applied to the nail from the [[moment]]''' |
Moment = 5.7Nm | Moment = 5.7Nm | ||
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<math>F = 142.5N</math> | <math>F = 142.5N</math> | ||
| − | | style="height:20px; width:200px; text-align: | + | | style="height:20px; width:200px; text-align:center;" |'''3. Calculate the Force applied to the nail from the [[moment]]''' |
Moment = 6.0Nm | Moment = 6.0Nm | ||
Revision as of 15:47, 11 February 2019
Contents
Key Stage 3
Meaning
A moment is the turning effect of a force.
About Moments
- When a force acts on an object with a pivot it becomes a turning force called a moment.
- A moment can be calculated by multiplying a force by the distance from a pivot.
- The units of a moment are Newton Metres (Nm).
- Moments can be used to make Force Multipliers using a pivot and lever.
- The longer the lever, the larger the moment that can be produced.
 |
| Using moments an effort can be used to lift a load. If the pivot is closer to the load than the effort then the force of effort can be smaller than the load to lift the object. |
Equation
Moment = Force x Perpendicular distance from the pivot.
\[M = F \times d\] Where:
- M = Moment
- F = Force
- d = Perpendicular distance from the pivot.
Example Calculations
| A 20N force of effort is applied at a perpendicular distance of 0.15m from the pivot. Calculate the Moment. | A 20N force of effort is applied at a perpendicular distance of 14cm from the pivot. Calculate the Moment. | A 20N force of effort is applied at a perpendicular distance of 100mm from the pivot. Calculate the Moment. |
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 |
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|
Force = 20N Perpendicular distance = 0.15m \(M = F \times d\) \(M = 20 \times 0.15\) \(M = 3.0Nm\) |
Force = 20N Perpendicular distance = 14cm = 0.14m \(M = F \times d\) \(M = 20 \times 0.14\) \(M = 2.8Nm\) |
Force = 20N Perpendicular distance = 100mm = 0.10m \(M = F \times d\) \(M = 20 \times 0.10\) \(M = 2.0Nm\) |
Key Stage 4
Meaning
A moment is the turning effect of a force.
About Moments
- When a force acts on an object with a pivot it becomes a turning force called a moment.
- A moment can be calculated by multiplying a force by the distance from a pivot.
- The units of a moment are Newton Metres (Nm).
- Moments can be used to make Force Multipliers using a pivot and lever.
- The longer the lever, the larger the moment that can be produced.
|
| Using moments an effort can be used to lift a load. If the pivot is closer to the load than the effort then the force of effort can be smaller than the load to lift the object. |
Equation
Moment = Force x Perpendicular distance from the pivot.
\[M = F \times d\] Where:
- M = Moment
- F = Force
- d = Perpendicular distance from the pivot.
Example Calculations
| A hammer is used to pull out a nail from a wall. A 30N force of effort is applied at a perpendicular distance of 0.18m from the pivot. While the nail is 0.02m away from the pivot. Calculate the force applied to the nail at this point. | A hammer is used to pull out a nail from a wall. A 30N force of effort is applied at a perpendicular distance of 19cm from the pivot. While the nail is 4cm away from the pivot. Calculate the force applied to the nail at this point. | A hammer is used to pull out a nail from a wall. A 30N force of effort is applied at a perpendicular distance of 200mm from the pivot. While the nail is 60mm away from the pivot. Calculate the force applied to the nail at this point. | |||
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| A 30N force of effort is applied at a perpendicular distance of 0.18m from the pivot. Calculate the Moment. | A 30N force of effort is applied at a perpendicular distance of 19cm from the pivot. Calculate the Moment. | A 30N force of effort is applied at a perpendicular distance of 200mm from the pivot. Calculate the Moment. | |||
| 1. State the known quantities
Force = 30N Perpendicular distance between effort and pivot = 0.18m Perpendicular distance between effort and pivot = 0.02m |
1. State the known quantities
Force = 30N Perpendicular distance between effort and pivot = 19cm = 0.19m Perpendicular distance between effort and pivot = 4cm = 0.04m |
1. State the known quantities
Force = 30N Perpendicular distance between effort and pivot = 200mm = 0.200m Perpendicular distance between effort and pivot = 60mm = 0.06m |
2. Find the moment caused by the effort.
\(M = F \times d\) \(M = 30 \times 0.18\) \(M = 5.4Nm\) |
2. Find the moment caused by the effort.
Force = 30N Perpendicular distance = 19cm = 0.19m \(M = F \times d\) \(M = 30 \times 0.19\) \(M = 5.7Nm\) |
2. Find the moment caused by the effort.
Force = 30N Perpendicular distance = 200mm = 0.20m \(M = F \times d\) \(M = 30 \times 0.20\) \(M = 6.0Nm\) |
| 3. Calculate the Force applied to the nail from the moment
Moment = 5.4Nm Perpendicular distance = 0.02m \(M = F \times d\) \(5.4 = F \times 0.02\) \(F = \tfrac{5.4}{0.02}\) \(F = 270N\) |
3. Calculate the Force applied to the nail from the moment
Moment = 5.7Nm Perpendicular distance = 4cm = 0.04m \(M = F \times d\) \(5.7 = F \times 0.04\) \(F = \tfrac{5.7}{0.04}\) \(F = 142.5N\) |
3. Calculate the Force applied to the nail from the moment
Moment = 6.0Nm Perpendicular distance = 60mm = 0.06m \(M = F \times d\) \(6.0 = F \times 0.06\) \(F = \tfrac{6.0}{0.06}\) \(F = 100N\) |