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==Key Stage 3=====Meaning==='''Balanced Forces''' are [[ForcesForce|forces]] that are the same strength but acting in opposite directions. ===About Balanced Forces===: When [[force]]s are '''balanced''' an [[object]] will travel at a constant [[speed]] and in the same direction. {| class="wikitable"|-|[[File:BalancedForces1.png|center|150px]]|[[File:BalancedForces2.png|center|200px]]|[[File:BalancedForces3.png|center|200px]]|-| style="height:20px; width:200px; text-align:center;" |The 7[[Newton|N]] up is '''balanced''' by the 7[[Newton|N]] down. | style="height:20px; width:200px; text-align:center;" |The 4[[Newton|N]] left is '''balanced''' by the 4[[Newton|N]] right.| style="height:20px; width:200px; text-align:center;" |The 6[[Newton|N]] up is '''balanced''' by the 6[[Newton|N]] down and the 5[[Newton|N]] left is '''balanced''' by the 5[[Newton|N]] right.|} ==Key Stage 4=====Meaning==='''Balanced forces''' are [[force]] [[vector]]s which add together to make 0N [[Resultant Force|resultant force]]. ===About Balanced Forces===: When [[force]]s on an [[object]] are '''balanced''' there is no [[acceleration]] (change speed or direction).: '''Balanced forces''' are related to [[Newton's First Law]] of motion::: An [[object]] in motion will tend to stay in motion in a straight line and an [[object]] at [[rest]] will tend to stay at [[rest]] unless an [[Unbalanced Forces|unbalanced force]] acts upon it.: If the [[Resultant Force|resultant force]] on an [[object]] is zero, then the [[force]]s are '''balanced'''. ===Examples==={| class="wikitable"|-|[[File:BalancedForces4.png|center|200px]]|[[File:BalancedForces5.png|center|200px]]|[[File:BalancedForces6.png|center|200px]]|-| style="height:20px; width:200px; text-align:center;" |<math>F_R = F_{up} - F_{down}</math> <math>F_R = 3 - 3</math> <math>F_R = 0N</math> The [[force]]s are '''balanced'''.| style="height:20px; width:200px; text-align:center;" |<math>F_R = F_{right} - F_{left}</math> <math>F_R = 80 - 80</math> <math>F_R = 0N</math> The [[force]]s are '''balanced'''.| style="height:20px; width:200px; text-align:center;" |<math>F_{Horiztonal} = F_{right} - F_{left}</math> <math>F_{Horiztonal} = 40 - 40</math> <math>F_{Horiztonal} = 0N</math> <math>F_{Vertical} = F_{up} - F_{down}</math> <math>F_{Vertical} = 38 - 38</math> <math>F_{Vertical} = 0N</math> The [[force]]s are '''balanced'''.|} {| class="wikitable"|-|[[File:BalancedForces7.png|center|600px]]|-| style="height:20px; width:200px; text-align:center;" |Whether these [[force]]s are '''balanced''' can be found by [[Resolving Forces|resolving]] the blue [[force]] [[vector]]s into the [[horizontal]]. See [[Resolving Forces]]. <math>F_{right} = 50\cos37 + 50\cos37</math> <math>F_{right} = 79.86N</math> Since the [[angle]] in the question is given to two [[Significant Figures|significant figures]] the answer should also be quoted to two [[Significant Figures|significant figures]]. <math>F_{right} \approx 80N</math> <math>F_R = F_{right} - F_{left}</math> <math>F_R = 80 - 80</math> <math>F_R = 0N</math>|} ===References=======AQA====:[https://www.amazon.co.uk/gp/product/019835939X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=019835939X&linkCode=as2&tag=nrjc-21&linkId=57e96876985fc39b1a3d8a3e3dc238b6 ''Balanced forces, pages 114-133, GCSE Physics; Third Edition, Oxford University Press, AQA '']:[https://www.amazon.co.uk/gp/product/1782946403/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782946403&linkCode=as2&tag=nrjc-21&linkId=32a0abb60dff015b15b50e9b1d7b4644 ''Balanced forces, pages 133, 170, GCSE Combined Science Trilogy; Physics, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Balanced forces, pages 153, 166, 202, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/0008158770/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0008158770&linkCode=as2&tag=nrjc-21&linkId=ec31595e720e1529e49876c3866fff6e ''Balanced forces, pages 154-6, GCSE Physics; Student Book, Collins, AQA '']====Edexcel====:[https://www.amazon.co.uk/gp/product/1292120223/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120223&linkCode=as2&tag=nrjc-21&linkId=068ecf40278c32406a7f1c6e66751417 ''Balanced forces, page 13, GCSE Physics, Pearson Edexcel '']:[https://www.amazon.co.uk/gp/product/1292120193/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120193&linkCode=as2&tag=nrjc-21&linkId=572df39392fb4200db8391d98ae6314e ''Balanced forces, page 297, GCSE Combined Science, Pearson Edexcel '']