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→Example Calculations
====Finding Velocity from Mass and Momentum====
{| class="wikitable"
| style="height:20px; width:300px; text-align:center;" |A 700kg car has a [[momentum]] of 2.4x10<sup>4</sup>kgm/s. Calculate the [[velocity]] of the carcorrect to two [[Significant Figures|significant figures]].| style="height:20px; width:300px; text-align:center;" |QuestionAn [[asteroid]] with a [[mass]] of 77Mg has a [[momentum]] of 3.2x10<sup>9</sup>kgm/s. Calculate the [[velocity]] of the [[asteroid]] correct to two [[Significant Figures|significant figures]].
|-
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
m = 700kg
p = 2.4x10<sup>4</sup>kgm/s
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
m = 77Mg = 77x10<sup>6</sup>
p = 3.2x10<sup>9</sup>kgm/s
|-
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
<math>p = mv</math>
<math>2.4 \times 10^4 = 700v</math>
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
<math>p = mv</math>
<math>3.2 \times 10^9 = (77 \times 10^6 )v</math>
|-
| style="height:20px; width:300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
<math>v = \frac{2.4 \times 10^4}{700}</math>
<math>v = 34.285714m/s</math>
<math>v \approx 34m/s</math>
| style="height:20px; width:300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
<math>v = \frac{3.2 \times 10^9}{77 \times 10^6}</math>
<math>v = 41.558441m/s</math>
<math>v \approx 42m/s</math>
|}
====Finding Mass from Velocity and Momentum====
{| class="wikitable"
| style="height:20px; width:300px; text-align:center;" |QuestionA skydiver has a [[velocity]] of 53m/s and a [[momentum]] of 4400kgm/s. Calculate the [[mass]] of the skydiver correct to two [[Significant Figures|significant figures]].| style="height:20px; width:300px; text-align:center;" |QuestionA plane travelling with a [[velocity]] of 122m/s has a [[momentum]] of 9.2x10<sup>4</sup>kgm/s. Calculate the [[mass]] of the [plane]] correct to two [[Significant Figures|significant figures]].
|-
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
v = 53m/s
p = 4400kgm/s
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
v = 122m/s
p = 9.2x10<sup>4</sup>kgm/s
|-
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
<math>p = mv</math>
<math>4400 = 53m</math>
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
<math>p = mv</math>
<math>9.2 \times 10^4 = 122m</math>
|-
| style="height:20px; width:300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
<math>m = \frac{4400}{53}</math>
<math>m = 83.01887kg</math>
<math>m \approx 83kg</math>
| style="height:20px; width:300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
<math>m = \frac{9.2 \times 10^4}{122}</math>
<math>m = 754.0984kg</math>
<math>m \approx 750kg</math>
|}