G481.1 Motion

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Lesson 1- Physical Quantities+Units

Motion: What Physical Quantites are and what units go with them.
Using Numerical Prefixes.

Lesson 2 - Vectors and Scalars

Motion: What Vectors and Scalars are and examples of them.

Lesson 3 - Vector Addition

Motion: Adding Vectors in 2 dimensions and using Pythagoras' Theorem to find the size of the resultant.

Lesson 4 - Components of a vector

Motion: Finding the components of a resultant vector by using trigonometry.

Lesson 5 - Gatso Speed Cameras

Motion: HOW SCIENCE WORKS.
How GATSO Speed cameras work.

Lesson 6-Displacement Time Graphs

Motion: Defining displacement and using displacement-time graphs to describe motion.

Lesson 7 - Velocity Time Graphs

Motion: Defining velocity and using velocity-time graphs to describe motion.

Lesson 8 - Motion Graphs Review

Motion: Using displacement-time and velocity-time graphs to find velocity, acceleration and displacement.

Lesson 9 - Uniform Acceleration

Motion: Deriving the equations of motion (suvat equations) and using them.

Lesson 10 - Motion under Gravity

Motion: Practical use of the equations of motion. Describing an experiment to find acceleration due to gravity.

Lesson 11 - Projectiles intro

Motion: What a projectile is and what path one follows.

Lesson 12 - Projectiles challenge

Motion: Applying the equations of motion to projectile motion.

Lesson 13 - Projectiles Practise

Motion: Applying the equations of motion to projectile motion.

Lesson 14 - G481.1 Module Review

Motion: Test yourself on Motion.

Lesson 15 - Newton's 2nd Law

Forces in action: Using Newton's 2nd Law and defining the Newton.

Lesson 16 - Newton 2 practise

Forces in action: Questions using Newton's 2nd Law.

Lesson 17 - Non-Linear Motion

Forces in action: Describing the motion of projectiles travelling in a fluid.

Lesson 18 - Equilibrium Definitions

Forces in action: Describing equilibrium and using the triangle of forces.

Lesson 19 - Moments and Couples

Forces in action: Describing moments and couples.

Lesson 20 - Equilibrium Examples

Forces in action: Using the principle of moments to do questions involving practical situations.

Lesson 21 - Density and Pressure

Forces in action: Describing density and pressure and their units.

Lesson 22 - Forces on Vehicles

Forces in action: Describing the factors that affect stopping distance.

Lesson 23-Physics of vehicles intro

Forces in action: Describing how air bags, seat belts and crumple zones work and looking at how GPS works.

Lesson 24 - Physics of vehicles

Forces in action: Describing how forces are reduced by using air bags, seat belts and crumple zones.

Lesson 25 - G481.2 Review

Forces in action: Test yourself on Forces in action.

Lesson 26 - Work and energy

Work and Energy: Defining work done and the Joule and using the equation.

Lesson 27 - Energy Changes

Work and Energy: Defining the conservation of energy and describing some examples.

Lesson 28 - GPE to KE

Work and Energy: Describing the interchange between gravitational potential energy and kinetic energy using equations.

Lesson 29 - Power

Work and Energy: Describing power and the Watt.

Lesson 30 - Efficiency

Work and Energy: Describing energy efficiency.

Lesson 31 - Spring Constant

Work and Energy: Looking at elastic materials and using Hooke's Law.

Lesson 32 - Strain Energy

Work and Energy: Describing the energy stored in elastic materials.

Lesson 33 - Young Modulus

Work and Energy: Describing Stress and Strain of materials, the definition of the Young Modulus and describing experiments to find it.

Lesson 34 - Material Properties

Work and Energy: Defining the terms elastic deformation and plastic deformation of a material. Looking at stress strain graphs for ductile, brittle and polymeric materials.

Lesson 35 - G481 Review

Work and Energy: Test yourself on Work and Energy.

Lesson 7 –motion graphs: velocity and acceleration

 

Keywords

Displacement, Velocity,Speed, Instantaneous Speed, Speed Acceleration, Gradient.

Objectives

You should:

(c) apply graphical methods to represent displacement, speed, velocity and acceleration;
(d) determine velocity from the gradient of a displacement against time graph;
(e) determine displacement from the area under a velocity against time graph;
(f) determine acceleration from the gradient of a velocity against time graph.

Starter

Watch the video at the top of the page.

Introduction

Velocity-time graphs

The following are examples of graphs where velocity is varying with time.

Remember that velocity is a vector and so if the line is above zero on the y-axis it means there is a positive velocity and if it is below zero it is a negative velocity.

A slope means that the velocity is changing – acceleration. This can be getting quicker or getting slower (deceleration is also called retardation)

graph
A positive flat line shows that there is a constant (uniform) positive velocity.

graph
A rising positive line means that there is a constant positive acceleration.

graph
graph

Displacement

 

To find the displacement of an object using a velocity-time (v-t) graph we find the area underneath the graph.

Acceleration

To find the acceleration of an object using a v-t graph we take the gradient. If we have a sloping line we can find the instantaneous acceleration be taking a tangent at a point.

These ideas will be looked at in more detail in lesson 8.

 

For a printable version of these notes click here.

Development

Have a look at the following site and check your answers. Don't move on until you have correctly answered all the multiple choice questions and understand why they are correct:

If you would rather look at this site in a separate window, then follow the link: velocity-time graphs (http://dev.physicslab.org/Document.aspx?doctype=5&filename=Kinematics_
UniformAccelerationVelocityTimeGraphs1.xml)


Plenary - Check your understanding

Look at the graph and then answer the questions:

velocity time graph plenary

1 What does the slope of a velocity-time graph represent?
2 Calculate the gradient and give the units for each section: A; B and C.
3 What is the total displacement?

click here for the answer.

There is another quiz to do as well for some extra practise:

Don't move on until you have correctly answered all the multiple choice questions and understand why they are correct:

If you would rather look at this site in a separate window, then follow the link: velocity-time graphs (http://www.cbbs.org/physics11/velquiz.htm)

 

Outcomes

You should check through these outcomes. If there is anything you can't do, check through the page again before you do your homework.

(c) apply graphical methods to represent displacement, speed, velocity and acceleration;
(d) determine velocity from the gradient of a displacement against time graph;
(e) determine displacement from the area under a velocity against time graph;
(f) determine acceleration from the gradient of a velocity against time graph.

Homework

Now print out the Exam Questions and try them. These are the same standard as the questions you will get in your exam. As you get close to taking the exam, you should try to answer these so that it takes you 1 minute to get through a 1 mark question.

Below is a very rough guide to what grade you will achieve for the percentage gained.

%

Grade

80

A

70

B

60

C

50

D

40

E

Check with your teacher to find out what your target grade is based on how you did at key stage 4 but remeber some topics are easier than others and so it is the overall average that really counts.