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→Key Stage 4
v = The [[speed]] or [[velocity]] of the [[object]].
===Calculating Velocity from Kinetic Energy==={| class="wikitable"| style="height:20px; width:200px; text-align:center;" |A 75kg person has a '''kinetic energy''' of 96J while while walking. Calculate their [[speed]].| style="height:20px; width:200px; text-align:center;" |Question| style="height:20px; width:200px; text-align:center;" |Question|-| style="height:20px; width:200px; text-align:left;" |'''1. State the known quantities'''E<sub>k</sub> = 96J m = 75kg| style="height:20px; width:200px; text-align:left;" |'''1. State the known quantities'''| style="height:20px; width:200px; text-align:left;" |'''1. State the known quantities'''|-| style="height:20px; width:200px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].''' <math>E_k = \frac{1}{2} m v^2</math> <math>96 = \frac{1}{2} \times 75 \times v^2</math> <math>96 = 37.5v^2</math> | style="height:20px; width:200px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''| style="height:20px; width:200px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''|-| style="height:20px; width:200px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].''' <math>v^2 = \frac{96}{37.5}</math> <math>v = \sqrt{\frac{96}{37.5}}</math> <math>v = 1.6m/s</math> | style="height:20px; width:200px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''| style="height:20px; width:200px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''|}