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|[[File:UnbalancedForces3.png|center|200px]]
|-
| style="height:20px; width:200px; text-align:center;" |The 4[[Newton|N]] up and the 7[[Newton|N]] down mean the [[object]] will [[accelerate]] downwards due to a [[Resultant Force|resultant force]] of 3[[Newton|N]].| style="height:20px; width:200px; text-align:center;" |The 4[[Newton|N]] left and the 3[[Newton|N]] right mean the [[object]] will [[accelerate]] to the left due to a [[Resultant Force|resultant force]] of 1[[Newton|N]].| style="height:20px; width:200px; text-align:center;" |The 6[[Newton|N]] up is '''balanced''' by the 6[[Newton|N]] down but the 6[[Newton|N]] left and the 4[[Newton|N]] right mean the object will [[accelerate]] to the left due to a [[Resultant Force|resultant force]] of 2[[Newton|N]].
|}
==Key Stage 4==
===Meaning===
'''Unbalanced forces''' are [[force]] [[vector]]s which add together to make a (non-zero) [[Resultant Force|resultant force]].
===About Balanced Forces===
: When [[force]]s on an [[object]] are '''unbalanced''' it will [[accelerate]] (change speed or direction).
: '''Unbalanced 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 not zero, then the [[force]]s are '''unbalanced'''.
===Examples===
{| class="wikitable"
|-
|[[File:ResultantForce1.png|center|200px]]
|[[File:ResultantForce2.png|center|200px]]
|[[File:ResultantForce3.png|center|200px]]
|-
| style="height:20px; width:200px; text-align:center;" |
'''Choose which directions are positive.'''
Up is positive.
'''Calculate the [[Resultant Force]]'''
There is 29N up and 37N down.
F<sub>R</sub> = (+29N) + (-37N)
F<sub>R</sub> = -8N upwards
The [[force]]s are '''unbalanced'''.
| style="height:20px; width:200px; text-align:center;" |
'''Choose which directions are positive.'''
Right is positive.
'''Calculate the [[Resultant Force]]'''
There is 114N right and 105N left.
F<sub>R</sub> = (+114N) + (-105N)
F<sub>R</sub> = 9N right
The [[force]]s are '''unbalanced'''.
| style="height:20px; width:200px; text-align:center;" |
'''Choose which directions are positive.'''
Right is positive.
Up is positive.
'''Calculate the [[Resultant Force]]'''
There is 38N up and 38N down.
F<sub>R</sub> = (+38N) + (-38N)
F<sub>R</sub> = 0N upwards
The [[vertical]] [[force]]s are [[Balanced Forces|balanced]].
'''Calculate the [[Resultant Force]]'''
There is 50N right and 40N left.
F<sub>R</sub> = (+50N) + (-40N)
F<sub>R</sub> = 10N right
The [[horizontal]] [[force]]s are '''unbalanced'''.
|}
===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 ''Unbalanced forces, pages 118-119, GCSE Physics; Third Edition, Oxford University Press, 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 ''Unbalanced forces, pages 146, 156, 180-1, 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 ''Unbalanced forces, page 13, GCSE Physics, Pearson Edexcel '']