Monday, June 22, 2020






  1. O’ Level Study Notes All Subjects
  2. A’ Level Study Notes All Subjects
  3. Pats Papers


Concepts of Measurement
Explain the concepts of measurement
Measurement is the process of assigning numbers to observations or events.
Importance of Measurement in Real Life
Measurements are so often taken for granted,
we sometimes do not appreciate the grand importance measurements play in our lives. On a baseline level, measurements fall into the categories of weight, area, volume, length and even temperature. While we look at these various categories as stoic forms of mathematical measurements, a closer examination of things we do in everyday life reveals their clear importance.
Taking proper medicine. 
If you are ill (whether a serious or minor illness) you need to take your medicine and take it in the proper amount. If you take too little or too much then you are not going to get the proper benefit from it.
Cooking properly. 
Cooking of all forms is based on proper attention to measurement. Can you bake a chicken at 600 degrees? Well, you can but the results would be pretty catastrophic! Could you may a cup of tea by dipping a tea bag into a teaspoon of warm water?

Purchasing clothes.
Now, how important could measurements be when selecting clothes? After all, to look good in clothing the main thing you need to pay attention to is style, right? Well, if you weigh 200lbs you aren’t going to look stylish in an extra small shirt. Clothing is all based on size and proper fitting which are, of course, variants of measurement.
Playing sports. 
The importance of measurements may not necessarily reveal itself when you play sports but it is there in a big way. If you want to throw a runner out at first or make a 30 yard touchdown pass then you really need to be accurate and comes from a clear sense of depth and distance.
Making estimations. 
If you have to be at school at 9am what time would you have to leave in the morning if you are at your friend’s house. Often we do not have an exact answer so we need to make an estimation which is essentially a guess of measurement.
Keeping yourself warm or cool. 
If the temperature outside dips or increases you have to make an adjustment on your thermostat in order to remain at a safe and healthy temperature. Understanding the measurement scale of a thermostat is critical in this regard or else you may find yourself feeling rather uncomfortable.
Understanding weight.
 Is that object too heavy to pick up by yourself or do you need to use something to lift it? Some may think this is not important but it is pretty easy to hurt yourself if you lift objects that are too heavy.

Proper use of capacity. 
Just how many clothes can you fit in a dresser or closet without it becoming too crammed? Without a clear concept of capacity you might find yourself pouring an entire half gallon of orange juice into a small glass!
Telling time. 
The ability to tell time is all based on measurement principles. Whether you are using a digital clock or an hourglass these devices measure the passage of time. Now, imagine how chaotic the world would be if if was impossible to measure the passage of time.
How much weight is too much for a plane to take off or a car to move efficiently? How much fuel is needed to reach a certain point and how long will it take to get somewhere? Yes, measurements play a significant part in transportation.
This was saved for last because it is the common theme that is found in all the multitude of reasons for the importance of measurements. Measurements provide structure and remove the chaos that would result without any congruent method of understanding weight, mass, temperature, etc.
The Concept of Density of a Substance and its S.I Unit
Explain the concept of density of a substance and its S.I unit

The Density of a substance is its mass per unit volume.
The unit of density is kg/mˆ3. Other unit used is g/cmˆ3.Density of regular solid object can easily be found by direct and easy measurements.-It involves measuring the mass and calculating the volume as described in the experiment below.
The Density of Regular and Irregular Solids
Determine the density of regular and irregular solids
Activity 2
Aim;To measure the density of rectangular block.
Material and Apparatus :Ruler, beam balance and rectangular block.
Procedures:Using a beam balance measure mass of the block, m.Measure its length, width and height.
  • The mass of the rectangular block is m.
  • The volume of the rectangular block will be calculated by multiplying the obtained length, l height, h and width, w.
  • Volume, V = l x h x w, But; Density = mass/volume
  • The volume of a material can be obtained by using various methods depending on the shape of the material
Activity 3
Aim; To determine density of irregular solid.
Materials and apparatus:Irregular solid like stone, measuring cylinder, beam balance and water.
  • Obtain the mass of the given object using the beam balance.
  • Fill water to the measuring cylinder to the volume V₁.
  • Immerse the well tied irregular object totally in the cylinder containing water.
  • Record the new volume V₂.
  • Volume of irregular object = V₂ – V₁
  • Mass obtained = M

The Density of a Liquid
Determine the density of a liquid
Density of liquids can be determined by using a burrete or a density.
Activity 4
Aim: To determine density of liquids using a burette.
Materials and apparatus: Burette, beaker, beam balance and kerosene.
  • Record the mass of the empty beaker m₁ using a beam balance.
  • Pour the known volume of kerosene into the beaker by using bur rete, V.
  • Record the mass of the beaker and kerosene m₂.
Definition of the Relative Density of a Substance
Define the relative density of a substance
The Relative density of a substance is the ratio of its density to the density of water.The density of water has the density of approximately 1.0g/cm³ or 1000kg/m³.
Note:Since the density of pure water is 1g/cm³, the RD of a substance will be represented by the same number as its density in g/cm³.RD has no units as its ratio of same quantities.
Applications of Density and Relative Density in Real Life
Interpret applications of density and relative density in real life
Application of RD in real life.
  1. It is the key factor which is considered during the design of various structures and equipment. Eg. ships and planes.
  2. Density is considered during the selection of materials.
  3. Density is also considered during the design of equipment used in swimming.


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