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(Created page with "==Key Stage 4 Foundation== ===Meaning=== '''Newton's Second Law''' states that "Force = Mass x Acceleration, which means the acceleration of an object is Directly Pr...")
 
 
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<math>F=ma</math>
 
<math>F=ma</math>
  
Where:
+
Where
  
F = The [[Resultant Force]] on the [[object]].
+
<math>F</math> = The [[Resultant Force]] on the [[object]].
  
m = The [[mass]] of the [[object]].
+
<math>m</math> = The [[mass]] of the [[object]].
  
a = The [[acceleration]] of the [[object]].
+
<math>a</math> = The [[acceleration]] of the [[object]].
  
 
===Example Calculations===
 
===Example Calculations===
====Finding the Force given Mass and Acceleration===
+
====Finding the Force given Mass and Acceleration====
 
{| class="wikitable"
 
{| class="wikitable"
| style="height:20px; width:200px; text-align:center;" |A 2.3kg [[object]] [[accelerate]]s at a rate of 8.8m/s/s. Calculate the [[Resultant Force|resultant force]] acting on the [[object]] correct to two [[Significant Figures|significant figures]].
+
| style="height:20px; width:300px; text-align:center;" |A 2.3kg [[object]] [[accelerate]]s at a rate of 8.8m/s/s. Calculate the [[Resultant Force|resultant force]] acting on the [[object]] correct to two [[Significant Figures|significant figures]].
| style="height:20px; width:200px; text-align:center;" |A 5.5x10<sup>4</sup>kg rocket [[accelerate]]s at a rate of 61m/s/s. Calculate the [[Resultant Force|resultant force]] acting on the rocket correct to two [[Significant Figures|significant figures]].
+
| style="height:20px; width:300px; text-align:center;" |A 5.5x10<sup>4</sup>kg rocket [[accelerate]]s at a rate of 61m/s/s. Calculate the [[Resultant Force|resultant force]] acting on the rocket correct to two [[Significant Figures|significant figures]].
 
|-
 
|-
| style="height:20px; width:200px; text-align:left;" |'''1. State the known quantities'''
+
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
  
 
m = 2.3kg
 
m = 2.3kg
  
 
a = 8.8m/s/s
 
a = 8.8m/s/s
| style="height:20px; width:200px; text-align:left;" |'''1. State the known quantities'''
+
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
  
 
m = 5.5x10<sup>4</sup>kg
 
m = 5.5x10<sup>4</sup>kg
Line 36: Line 36:
 
a = 61m/s/s
 
a = 61m/s/s
 
|-
 
|-
| style="height:20px; width:200px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].'''
+
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].'''
  
 
<math>F=ma</math>
 
<math>F=ma</math>
Line 45: Line 45:
  
 
<math>F \approx 20N</math>
 
<math>F \approx 20N</math>
| style="height:20px; width:200px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].'''
+
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].'''
  
 
<math>F=ma</math>
 
<math>F=ma</math>
Line 56: Line 56:
 
|}
 
|}
  
====Finding the Acceleration given Mass and Force===
+
====Finding the Acceleration given Mass and Force====
 
{| class="wikitable"
 
{| class="wikitable"
| style="height:20px; width:200px; text-align:center;" |A 7kg [[object]] is subjected to a [[Resultant Force|resultant force]] of 53N. Calculate the [[acceleration]] of the [[object]] correct to two [[Significant Figures|significant figures]].
+
| style="height:20px; width:300px; text-align:center;" |A 7kg [[object]] is subjected to a [[Resultant Force|resultant force]] of 53N. Calculate the [[acceleration]] of the [[object]] correct to two [[Significant Figures|significant figures]].
| style="height:20px; width:200px; text-align:center;" |A 160g snooker ball experiences a [[Resultant Force|resultant force]] of 12N. Calculate the [[acceleration]] of the snooker ball correct to two [[Significant Figures|significant figures]].
+
| style="height:20px; width:300px; text-align:center;" |A 160g snooker ball experiences a [[Resultant Force|resultant force]] of 12N. Calculate the [[acceleration]] of the snooker ball correct to two [[Significant Figures|significant figures]].
 
|-
 
|-
| style="height:20px; width:200px; text-align:left;" |'''1. State the known quantities'''
+
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
  
 
m = 7kg
 
m = 7kg
  
 
F = 53N
 
F = 53N
| style="height:20px; width:200px; text-align:left;" |'''1. State the known quantities'''
+
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
  
 
m = 160g = 0.16kg
 
m = 160g = 0.16kg
Line 72: Line 72:
 
F = 12N
 
F = 12N
 
|-
 
|-
| style="height:20px; width:200px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
+
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
  
 
<math>F=ma</math>
 
<math>F=ma</math>
  
 
<math>53=7a</math>
 
<math>53=7a</math>
| style="height:20px; width:200px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
+
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
  
 
<math>F=ma</math>
 
<math>F=ma</math>
Line 83: Line 83:
 
<math>12=0.16a</math>
 
<math>12=0.16a</math>
 
|-
 
|-
| style="height:20px; width:200px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
+
| style="height:20px; width:300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
 
<math>a = \frac{53}{7}</math>
 
<math>a = \frac{53}{7}</math>
  
Line 89: Line 89:
  
 
<math>a \approx 7.6m/s/s</math>
 
<math>a \approx 7.6m/s/s</math>
| style="height:20px; width:200px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
+
| style="height:20px; width:300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
 
<math>a = \frac{12}{0.16}</math>
 
<math>a = \frac{12}{0.16}</math>
  
Line 108: Line 108:
 
<math>F=ma</math>
 
<math>F=ma</math>
  
Where:
+
Where
  
F = The [[Resultant Force]] on the [[object]].
+
<math>F</math> = The [[Resultant Force]] on the [[object]].
  
m = The [[Inertial Mass]] of the [[object]].
+
<math>m</math> = The [[Inertial Mass]] of the [[object]].
  
a = The [[acceleration]] of the [[object]].
+
<math>a</math> = The [[acceleration]] of the [[object]].
  
 
===Example Calculations===
 
===Example Calculations===
====Finding the Force given Mass and Acceleration===
+
====Finding the Force given Inertial Mass and Acceleration====
 
{| class="wikitable"
 
{| class="wikitable"
| style="height:20px; width:200px; text-align:center;" |A 1.23Mg [[object]] [[accelerate]]s at a rate of 5.3x10<sup>-2</sup>m/s/s. Calculate the [[Resultant Force|resultant force]] acting on the [[object]] correct to two [[Significant Figures|significant figures]].
+
| style="height:20px; width:300px; text-align:center;" |A 1.23Mg [[object]] [[accelerate]]s at a rate of 5.3x10<sup>-2</sup>m/s/s. Calculate the [[Resultant Force|resultant force]] acting on the [[object]] correct to two [[Significant Figures|significant figures]].
| style="height:20px; width:200px; text-align:center;" |A 1.7x10ng cell [[accelerate]]s at a rate of 320m/s/s. Calculate the [[Resultant Force|resultant force]] acting on the rocket correct to two [[Significant Figures|significant figures]].
+
| style="height:20px; width:300px; text-align:center;" |A 1.7x10ng cell [[accelerate]]s at a rate of 320m/s/s. Calculate the [[Resultant Force|resultant force]] acting on the rocket correct to two [[Significant Figures|significant figures]].
 
|-
 
|-
| style="height:20px; width:200px; text-align:left;" |'''1. State the known quantities'''
+
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
  
 
m = 1.23Mg = 1230kg
 
m = 1.23Mg = 1230kg
  
 
a = 5.3x10<sup>-2</sup>m/s/s
 
a = 5.3x10<sup>-2</sup>m/s/s
| style="height:20px; width:200px; text-align:left;" |'''1. State the known quantities'''
+
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
  
 
m = 1.7ng = 1.7x10<sup>-12</sup>kg
 
m = 1.7ng = 1.7x10<sup>-12</sup>kg
Line 133: Line 133:
 
a = 320m/s/s.
 
a = 320m/s/s.
 
|-
 
|-
| style="height:20px; width:200px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].'''
+
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].'''
  
 
<math>F=ma</math>
 
<math>F=ma</math>
Line 142: Line 142:
  
 
<math>F \approx 65N</math>
 
<math>F \approx 65N</math>
| style="height:20px; width:200px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].'''
+
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].'''
  
 
<math>F=ma</math>
 
<math>F=ma</math>
Line 153: Line 153:
 
|}
 
|}
  
====Finding the Acceleration given Mass and Force===
+
====Finding the Acceleration given Inertial Mass and Force====
 
{| class="wikitable"
 
{| class="wikitable"
| style="height:20px; width:200px; text-align:center;" |A 9.2g [[object]] is subjected to a [[Resultant Force|resultant force]] of 3.7kN. Calculate the [[acceleration]] of the [[object]] correct to two [[Significant Figures|significant figures]].
+
| style="height:20px; width:300px; text-align:center;" |A 9.2g [[object]] is subjected to a [[Resultant Force|resultant force]] of 3.7kN. Calculate the [[acceleration]] of the [[object]] correct to two [[Significant Figures|significant figures]].
| style="height:20px; width:200px; text-align:center;" |A 333 tonne passenger plane experiences a [[Resultant Force|resultant force]] of 1.008MN. Calculate the [[acceleration]] of the passenger plane correct to two [[Significant Figures|significant figures]].
+
| style="height:20px; width:300px; text-align:center;" |A 333 tonne passenger plane experiences a [[Resultant Force|resultant force]] of 1.008MN. Calculate the [[acceleration]] of the passenger plane correct to two [[Significant Figures|significant figures]].
 
|-
 
|-
| style="height:20px; width:200px; text-align:left;" |'''1. State the known quantities'''
+
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
  
 
m = 9.2g = 0.0092kg
 
m = 9.2g = 0.0092kg
  
 
F = 3.7kN = 3700N
 
F = 3.7kN = 3700N
| style="height:20px; width:200px; text-align:left;" |'''1. State the known quantities'''
+
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
  
 
m = 333 tonne = 3.33 x 10<sup>5</sup>kg
 
m = 333 tonne = 3.33 x 10<sup>5</sup>kg
Line 169: Line 169:
 
F = 1.008MN = 1.008 x 10<sup>6</sup>N
 
F = 1.008MN = 1.008 x 10<sup>6</sup>N
 
|-
 
|-
| style="height:20px; width:200px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
+
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
  
 
<math>F=ma</math>
 
<math>F=ma</math>
  
 
<math>3700=0.0092a</math>
 
<math>3700=0.0092a</math>
| style="height:20px; width:200px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
+
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
  
 
<math>F=ma</math>
 
<math>F=ma</math>
Line 180: Line 180:
 
<math>1.008 \times 10^6 = (3.33 \times 10^5 )a</math>
 
<math>1.008 \times 10^6 = (3.33 \times 10^5 )a</math>
 
|-
 
|-
| style="height:20px; width:200px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
+
| style="height:20px; width:300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
 
<math>a = \frac{3700}{0.0092}</math>
 
<math>a = \frac{3700}{0.0092}</math>
  
Line 186: Line 186:
  
 
<math>a \approx 4.0 \times 10^5m/s/s</math>
 
<math>a \approx 4.0 \times 10^5m/s/s</math>
| style="height:20px; width:200px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
+
| style="height:20px; width:300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
 
<math>a = \frac{1.008 \times 10^6}{3.33 \times 10^5}</math>
 
<math>a = \frac{1.008 \times 10^6}{3.33 \times 10^5}</math>
  
Line 193: Line 193:
 
<math>a \approx 3.0m/s/s</math>
 
<math>a \approx 3.0m/s/s</math>
 
|}
 
|}
 +
 +
====Finding the Inertial Mass given the Force and Acceleration====
 +
{| class="wikitable"
 +
| style="height:20px; width:300px; text-align:center;" |An [[object]] is subjected to a [[Resultant Force|resultant force]] of 92N and [[accelerate]]s at a rate of 0.42m/s/s. Calculate the [[Inertial Mass|inertial mass]] of the [[object]] correct to two [[Significant Figures|significant figures]].
 +
| style="height:20px; width:300px; text-align:center;" |The brakes of a car provide a [[force]] of 12kN and are able to [[decelerate]] it at a rate of 8.7m/s/s. Calculate the [[Inertial Mass|intertial mass]] of the car correct to two [[Significant Figures|significant figures]].
 +
|-
 +
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
 +
 +
a = 0.42m/s/s
 +
 +
F = 92N
 +
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
 +
 +
a = 8.7m/s/s
 +
 +
F = 12kN = 12 x 10<sup>3</sup>N
 +
|-
 +
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
 +
 +
<math>F=ma</math>
 +
 +
<math>92=0.42m</math>
 +
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].'''
 +
 +
<math>F=ma</math>
 +
 +
<math>12 \times 10^3 = 8.7m</math>
 +
|-
 +
| style="height:20px; width:300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
 +
<math>m = \frac{92}{0.42}</math>
 +
 +
<math>m = 219.047619kg</math>
 +
 +
<math>m \approx 220kg</math>
 +
| style="height:20px; width:300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].'''
 +
<math>m = \frac{12 \times 10^3}{8.7}</math>
 +
 +
<math>m = 1379.31034kg</math>
 +
 +
<math>m \approx 1400kg</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 ''Newton’s Second Law of motion, pages 144-145, 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 ''Newton’s Second Law, pages 164, 165, 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 ''Newton’s Second Law, pages 196, 197, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']
 +
:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe10102 ''Newton’s Second Law, pages 212, 214, GCSE Combined Science; The Revision Guide, CGP, AQA '']
 +
:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe10103 ''Newton’s Second Law; investigating, page 214, GCSE Combined Science; The Revision Guide, CGP, 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 ''Newton’s Second Law; investigating, pages 167, 168, 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 ''Newton’s Second Law; investigating, pages 199, 200, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']
 +
 +
====Edexcel====
 +
 +
:[https://www.amazon.co.uk/gp/product/1782945741/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945741&linkCode=as2&tag=nrjc-21&linkId=30da4f2178da182547b62a7329d13b57 ''Newton’s Second Law, pages 149, 151, 154, GCSE Combined Science; The Revision Guide, CGP, Edexcel '']
 +
:[https://www.amazon.co.uk/gp/product/1782945733/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945733&linkCode=as2&tag=nrjc-21&linkId=2a2dbec9db6bf5766c0458d908fa0a52 ''Newton’s Second Law, pages 16, 18, 21, GCSE Physics; The Revision Guide, CGP, 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 ''Newton’s Second Law, pages 18-19, 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 ''Newton’s Second Law, pages 302-303, GCSE Combined Science, Pearson Edexcel '']
 +
:[https://www.amazon.co.uk/gp/product/1782948163/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782948163&linkCode=as2&tag=nrjc-21&linkId=0fdbfd5dd397d6e24a9dfb250f08587f ''Newton’s Second Law, pages 35, 36, 46, GCSE Physics, CGP, Edexcel '']
 +
:[https://www.amazon.co.uk/gp/product/1782948163/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782948163&linkCode=as2&tag=nrjc-21&linkId=0fdbfd5dd397d6e24a9dfb250f08587f ''Newton’s Second Law; investigating, pages 39, 40, GCSE Physics, CGP, Edexcel '']

Latest revision as of 16:16, 23 November 2019

Key Stage 4 Foundation

Meaning

Newton's Second Law states that "Force = Mass x Acceleration, which means the acceleration of an object is directly proportional to the resultant force acting upon it."

About Newton's Second Law

Newton's Second Law can be used to calculate the acceleration of an object given its mass and the resultant force acting upon it.

Equation

Force = Mass x Acceleration

\(F=ma\)

Where

\(F\) = The Resultant Force on the object.

\(m\) = The mass of the object.

\(a\) = The acceleration of the object.

Example Calculations

Finding the Force given Mass and Acceleration

A 2.3kg object accelerates at a rate of 8.8m/s/s. Calculate the resultant force acting on the object correct to two significant figures. A 5.5x104kg rocket accelerates at a rate of 61m/s/s. Calculate the resultant force acting on the rocket correct to two significant figures.
1. State the known quantities

m = 2.3kg

a = 8.8m/s/s

1. State the known quantities

m = 5.5x104kg

a = 61m/s/s

2. Substitute the numbers into the equation and solve.

\(F=ma\)

\(F=2.3 \times 8.8\)

\(F=20.24N\)

\(F \approx 20N\)

2. Substitute the numbers into the equation and solve.

\(F=ma\)

\(F=5.5 \times 10^4 \times 61\)

\(F=3355000N\)

\(F \approx 3.4 \times 10^6 N\)

Finding the Acceleration given Mass and Force

A 7kg object is subjected to a resultant force of 53N. Calculate the acceleration of the object correct to two significant figures. A 160g snooker ball experiences a resultant force of 12N. Calculate the acceleration of the snooker ball correct to two significant figures.
1. State the known quantities

m = 7kg

F = 53N

1. State the known quantities

m = 160g = 0.16kg

F = 12N

2. Substitute the numbers and evaluate.

\(F=ma\)

\(53=7a\)

2. Substitute the numbers and evaluate.

\(F=ma\)

\(12=0.16a\)

3. Rearrange the equation and solve.

\(a = \frac{53}{7}\)

\(a = 7.571m/s/s\)

\(a \approx 7.6m/s/s\)

3. Rearrange the equation and solve.

\(a = \frac{12}{0.16}\)

\(a = 75m/s/s\)

Key Stage 4 Higher

Meaning

Newton's Second Law states that "Force = Mass x Acceleration, which means the acceleration of an object is directly proportional to the resultant force acting upon it."

About Newton's Second Law

Newton's Second Law can be used to calculate the acceleration of an object given its mass and the resultant force acting upon it.
Newton's Second Law provides a definition for inertial mass as the ratio of force to the acceleration of an object \(m= \frac{F}{a}\).

Equation

Force = (Inertial Mass) x Acceleration

\(F=ma\)

Where

\(F\) = The Resultant Force on the object.

\(m\) = The Inertial Mass of the object.

\(a\) = The acceleration of the object.

Example Calculations

Finding the Force given Inertial Mass and Acceleration

A 1.23Mg object accelerates at a rate of 5.3x10-2m/s/s. Calculate the resultant force acting on the object correct to two significant figures. A 1.7x10ng cell accelerates at a rate of 320m/s/s. Calculate the resultant force acting on the rocket correct to two significant figures.
1. State the known quantities

m = 1.23Mg = 1230kg

a = 5.3x10-2m/s/s

1. State the known quantities

m = 1.7ng = 1.7x10-12kg

a = 320m/s/s.

2. Substitute the numbers into the equation and solve.

\(F=ma\)

\(F=1230 \times 5.3 \times 10^{-2}\)

\(F=65.19\)

\(F \approx 65N\)

2. Substitute the numbers into the equation and solve.

\(F=ma\)

\(F=1.7 \times 10^{-12} \times 320\)

\(F=0.000000000544N\)

\(F \approx 5.4 \times 10^{-10}N\)

Finding the Acceleration given Inertial Mass and Force

A 9.2g object is subjected to a resultant force of 3.7kN. Calculate the acceleration of the object correct to two significant figures. A 333 tonne passenger plane experiences a resultant force of 1.008MN. Calculate the acceleration of the passenger plane correct to two significant figures.
1. State the known quantities

m = 9.2g = 0.0092kg

F = 3.7kN = 3700N

1. State the known quantities

m = 333 tonne = 3.33 x 105kg

F = 1.008MN = 1.008 x 106N

2. Substitute the numbers and evaluate.

\(F=ma\)

\(3700=0.0092a\)

2. Substitute the numbers and evaluate.

\(F=ma\)

\(1.008 \times 10^6 = (3.33 \times 10^5 )a\)

3. Rearrange the equation and solve.

\(a = \frac{3700}{0.0092}\)

\(a = 402173.913m/s/s\)

\(a \approx 4.0 \times 10^5m/s/s\)

3. Rearrange the equation and solve.

\(a = \frac{1.008 \times 10^6}{3.33 \times 10^5}\)

\(a = 3.027m/s/s\)

\(a \approx 3.0m/s/s\)

Finding the Inertial Mass given the Force and Acceleration

An object is subjected to a resultant force of 92N and accelerates at a rate of 0.42m/s/s. Calculate the inertial mass of the object correct to two significant figures. The brakes of a car provide a force of 12kN and are able to decelerate it at a rate of 8.7m/s/s. Calculate the intertial mass of the car correct to two significant figures.
1. State the known quantities

a = 0.42m/s/s

F = 92N

1. State the known quantities

a = 8.7m/s/s

F = 12kN = 12 x 103N

2. Substitute the numbers and evaluate.

\(F=ma\)

\(92=0.42m\)

2. Substitute the numbers and evaluate.

\(F=ma\)

\(12 \times 10^3 = 8.7m\)

3. Rearrange the equation and solve.

\(m = \frac{92}{0.42}\)

\(m = 219.047619kg\)

\(m \approx 220kg\)

3. Rearrange the equation and solve.

\(m = \frac{12 \times 10^3}{8.7}\)

\(m = 1379.31034kg\)

\(m \approx 1400kg\)

References

AQA

Newton’s Second Law of motion, pages 144-145, GCSE Physics; Third Edition, Oxford University Press, AQA
Newton’s Second Law, pages 164, 165, GCSE Combined Science Trilogy; Physics, CGP, AQA
Newton’s Second Law, pages 196, 197, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA
Newton’s Second Law, pages 212, 214, GCSE Combined Science; The Revision Guide, CGP, AQA
Newton’s Second Law; investigating, page 214, GCSE Combined Science; The Revision Guide, CGP, AQA
Newton’s Second Law; investigating, pages 167, 168, GCSE Combined Science Trilogy; Physics, CGP, AQA
Newton’s Second Law; investigating, pages 199, 200, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA

Edexcel

Newton’s Second Law, pages 149, 151, 154, GCSE Combined Science; The Revision Guide, CGP, Edexcel
Newton’s Second Law, pages 16, 18, 21, GCSE Physics; The Revision Guide, CGP, Edexcel
Newton’s Second Law, pages 18-19, GCSE Physics, Pearson Edexcel
Newton’s Second Law, pages 302-303, GCSE Combined Science, Pearson Edexcel
Newton’s Second Law, pages 35, 36, 46, GCSE Physics, CGP, Edexcel
Newton’s Second Law; investigating, pages 39, 40, GCSE Physics, CGP, Edexcel