An introduction to physical sciences

1. AN INTRODUCTION TO THE POSSIBILITIES
OF PHYSICAL SCIENCES FOR GRADE 10
DUMISANI CHAUKE201407509
UNIVERSITYOF JOHANNESBURG
2016

2. TABLE OF CONTENTS
1. INTRODUCTION……………………………………………………………………………1
2. LEARNING OUTCOMES…………………………………………………………………2
3. VECTORS AND SCALARQUANTITIES ………………………………………………3
3.1 DIFFERETYPES VECTORAND SCALARQUANTIES……………….…...3
3.2 VECTORS AND SCALARADDITION…………………………………………. 4-5
4. ACIDS AND BASES ………………………………………………………………………..6
4.1. PROPERTIES OF ACIDS AND BASES………………………………………….7
4.2 Experiment on acids and bases………………………………………………..8-10
5. Summative assessment…………………………………………………………………11-12
6. Assessmentmemo…………………………………………………………………………13-14

3. Physical science is a subject that shows us the great possibilities of the
things of the world around us. As human beings it is very important for
us to know how the world around us operates.This can help us to be
able to use everything around us to the best of our benefit.
As a subjectphysical science has its own language. Therefore it is very
important for us to familiarise ourselves with this language of science as
sometimesthe use of some conceptsin everyday life contradicts its use
in physical sciences. Like the use of the word speed in everyday life.
Physical Science requires learners to have a scientific approach to
solving problems.This means that for every claim a learner makes about
a certain topic they must have evidence to back it up. After that they
must be able to presenta convincing argument where they apply their
reasoning skills.
A lot of things that happen in everyday life that seem unexplainable are
regarded as magic to many. Science is a subjectthat can help learners
to develop critical thinking skills as it encourages learners to always
seek a differentexplanation for why things happen.
Here is a link to an online tool that can help you understand what
physical science is a little bit more
https://www.instagrok.com/results.html?query=physical%20science
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4. LEARNING OUTCOMES
At the end of using this eBooklearners should be able to
1. Define what is a physical property
2. List differenttypes of vector and scalar quantities
3. To perform calculations involving vectors and scalar quantities
4. To differentiate between acids ands and bases
5. Give the properties of acids and bases
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5. VECTORS AND SCALAR QUANTIES
There are many things in our everyday lives that we sometimes
need to measure and they are called physical properties. These
physical properties can be subdivided into scalar and vector
quantities. For example take a look at the following picture
Looking at this picture I can be able to measure the speed and
velocity of the car. The mass of the car can also be measured
and then the weight of the car. I can also be able to measure
the length and width of the car.
These different things which we can measure from the car can
be classified as scalar and vector quantities. A vector is a
quantity that has both magnitude and direction. A scalar
quantity is a quantity that only has magnitude.
From the different the things that can be measured from the car
please define and classify them as scalar or vector quantities.
You can include others that you can think of. (Marks 16)
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6. Vectors and Scalar addition
Scalar addition
Since a scalar quantity only has magnitude, the magnitudes that need to
be added are just added without considerationof direction.
Here is an example of scalar addition
A learners walks a distance of 1000 meters to school.How much
distance does he/ she cover in a day because of going and coming back
from school?
Reasoning strategy
Distance is a scalar quantity therefore only has magnitude. The learner’s
walks 1000 meters to schooland 1000 meters back from school
Answer
1000m + 1000m = 2000m of distance covered.
VECTOR ADDITION
A vector quantity has both magnitude and direction. Therefore we need
to take the direction into consideration when adding vectors.
Here is an example of a vector addition
The people on the left of the picture are pulling the rope with a force of
20 Newton and the ones on the right are pulling with a force of 30
Newton. Calculate the net force applied
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7. Reasonig strategy
A force is vector quantity. So both magnitude and direction are
important. First choose one direction to be positive and the one opposite
that direction will be negative. I am choosing to the right as being
positve.
Answer
30N + (-20N) = 10 N to the right
Here is a video link for YouTube so that you get a better
understanding of vectors and scalar quantities.
https://www.youtube.com/watch?v=g82n3xayn2s
There is an activity for you to do on bsocrative. The room name is
CHAUKE 1505. Here is the linkhttps://b.socrative.com/student/#quiz
Please also do the following activity on vector and scalar addition.
1. A person pushes a trolley 5 meters to the east and then 2
meters to the west calculate total distance and displacement.
2. A person pushes a box with a force of 5N and the floor applies a
frictional force of 3N to the box. Calculate the net force on the
box.
3. A car travels at a velocity of 5 meters per second to the right
and then turns back and travels at a velocity of 1 meter per
second, calculate its total velocity.
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8. ACIDS AND BASES
Acids and bases form part of many household products. Acids are
substances which produce positive hydrogen ions in a solution. A
base is a substance that produces a hydroxide ions in a solution.
The strengths of both acids and bases can be measured using a PH
scale
Here are examples of acids and bases in our homes.
Watch this video to get a better understanding of acids and bases.
https://www.youtube.com/watch?v=tNvP3-174_
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9. ACIDS AND BASES PROPERTIES
From the picture you can see that both acids and bases can burn
your skin. Not all of them can do this but strong acids and bases are
the ones which can burn your skin if not taken care of properly.
Hence please do not play with these at home. An acid which
completely dissociates in water is called a strong acid and a base
which completes dissociates in water is called a strong base.
Perform this experiment at home
1. Get an egg, container and vinegar.
2. Place the egg in the container and add vinegar.
3. Leave the mixture for two days and then empty the vinegar.
4. Add new vinegar to the container and leave the mixture for
three more days.
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10. After finishing the experiment write a scientific report about what
happened to the shell of the egg. The rubric for the experiment is
below
To get a better understanding of acids and bases you are all required
to search for Phet simulations on your computer and choose Acid
base solution. This online tool will enable you to perform simple
experiments about acids and bases which can enhance your
knowledge on the topic. Here is the link to the simulation
https://phet.colorado.edu/en/simulation/acid-base-solutions
Please enter this link for our discussion about the importance of
acids and bases in our lives.
https://app.schoology.com/group/836332501.
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11. You are also required to perform this experiment on acids and bases
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12. Here is the rubric for the experiment
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13. Summative assessment
I designed this assessment so that I can be able to see whether the
learning outcomes for this book have been achieved. Doing this task
will help you to see where you need to improve. In this task I will
require you to mark the work for yourself to test your understanding
and I will then moderate the task after you have marked.
Question one
Define the following (8)
1. Vector quantity
2. Scalar quantity
3. Distance.
4. Velocity
5. Acid
6. Base
7. PH Scale
8. Strong acid
Question 2
Choose the correct answer from the following
1. All the following are vector quantities except for one which one
is it.(1)
a. Speed
b. Displacement
c. Force
d. Weight
2. Which one of the following is not a physical property(1)
a. Length
b. Width
c. Loudness
d. Speed
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14. 3. One of the following statements about acids is false(1)
a. An acid is a substance that produces positive hydrogen ions
in a solution
b. An acid can neutralize a base.
c. A weak acid can burn your skin.
d. Acids have a PH of less than seven
Question 3
Calculate the following.
1. The net fox acting on a box if two forces each of 5N acts on
the box in the same direction. (3)
2. The total distance covered and Displacement covered when
a person walks along a circular path with a length of 50m.
Starting from a place and ending at that place.(6)
Question 4
Tabulate the 4 main differences between acids and bases. (8)
Question 5
1. You are have been bitten by a bee and its sting is acidic.
What can you use to stop the burning of the sting and
why?(2)
2. A person wants to push a box from a floor which can apply a
maximum frictional force of 5N. What can you advise the
person to do in order for them to be able to move the
box.(2)
3. You want to swim at home and you discover that the water
in your swimming pool is very acidic what common
household chemical can be used to make it better for
swimming.(2) Total marks 34
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15. Memo for summative assessment
Question one
1- A quantity that has both magnitude and direction.
2- A quantity that has only magnitude
3- Total length of a path taken
4- Rate of change in displacement
5- A substance that produces positive hydrogen ions
6- A substance that produces negative hydroxide ions
7- Scale used to measure the strength of acids and bases.
8- An acid that completely dissociates in water.
Question two
1. A
2. C
3. C
Question three
1. 10 N
2. Distance=50 m Displacement = 0m
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16. Question four
ACID BASE
Has a PH of less than 7 Has a PH of more than 7
Produces positive hydrogen
ions
Produces negative hydroxide
ions
Turns blue litmus paper red. Turns red litmus paper blue
Acids Bitter
Question five
1. A soap can be used to clean the sting. A soap is a base
therefore it can neutralize the sting which is an acid.
2. The person can apply a force that is greater than 5N to
overcome the force of friction and move the box
3. Ammonia can be used to neutralize the acidic water and it is
one of most common used substances for cleaning pools.
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