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Mathematics

Grade 9

Algebra and geometry

Module 7

Space and shape

Activity 1:

To understand the structure of some regular right prisms

[LO 3.3, 3.4]

A. Building cont a iners

You will be given a sheet of shapes. You will need a ruler that you can measure with, a pair of scissors and glue or sticky tape. Colouring pens will also be helpful. Do the following with these shapes:

  1. Carefully measure all the lines and write down your measurements ( you should be able to measure to the nearest half–millimetre). You must also do your best to measure the radius (or diameter) of the circle. If you have a protractor available, find out where the 90°–angles are.
  2. Using these measurements, calculate the areas of the different shapes, and add the parts together to find out the total area of each of the four shapes. Set your work out very clearly so that anybody can understand what you have done. Use the proper names for the shapes you describe.

For example, for the last figure you could say:

Total area = small rectangle + small rectangle + large rectangle

= ( l × b ) + ( l × b ) + ( l × b )

and so on . . . (Remember to use appropriate units.)

  1. Very carefully cut out the given shapes. You can colour these shapes to make it easier to see which the top and base are, and which the sides (the sides are striped). Now fold them and use tape, or glue and paper strips, to make four boxes. Keep the sides with the dotted lines on the outside.
  2. Write down what the Total Surface Area (TSA) of each shape is. (You have already calculated the answer!)
  3. Work in groups of two or three to try to find out how many 1cm × 1cm blocks will fit into each box. This is called the volume of the box. If you can find a method or a formula that will work with each of the four shapes, write that down carefully.
  4. At the end of this exercise, you should have two formulas.

B. Right prisms

  • Each of the four boxes is a right prism . These are shapes with a top and base that are exactly the same size and shape, and sides that go up straight at right angles to the base. Look around to see whether you can discover shapes with these characteristics.
  • We name right prisms according to the shape of the base, e.g. square prism, rectangular prism, triangular prism and circular prism (cylinder).
  • Are these two shapes right prisms? Describe the shape of the base of each, and confirm whether the sides go straight up at right angles to the base.
  • What kind of work did you do in this section? Score yourself in this table.
Did i work Excellent Adequately Not well enough
well with my team?
according to instructions?
carefully?
accurately?
neatly?

C. Formul a s

  • To calculate the total surface area (TSA) and volume (V) of any right prism we use the following general formulas: (Please note that H refers to the prism height.)

TSA = 2 × base area + sides area and V = base area × prism height

Here are some important e x amples. These are the cut–out prisms you made into boxes. Please note how each part of the calculation is done separately and then put into the formula at the end.

  1. Squ a re prism :

Questions & Answers

Three charges q_{1}=+3\mu C, q_{2}=+6\mu C and q_{3}=+8\mu C are located at (2,0)m (0,0)m and (0,3) coordinates respectively. Find the magnitude and direction acted upon q_{2} by the two other charges.Draw the correct graphical illustration of the problem above showing the direction of all forces.
Kate Reply
To solve this problem, we need to first find the net force acting on charge q_{2}. The magnitude of the force exerted by q_{1} on q_{2} is given by F=\frac{kq_{1}q_{2}}{r^{2}} where k is the Coulomb constant, q_{1} and q_{2} are the charges of the particles, and r is the distance between them.
Muhammed
What is the direction and net electric force on q_{1}= 5µC located at (0,4)r due to charges q_{2}=7mu located at (0,0)m and q_{3}=3\mu C located at (4,0)m?
Kate Reply
what is the change in momentum of a body?
Eunice Reply
what is a capacitor?
Raymond Reply
Capacitor is a separation of opposite charges using an insulator of very small dimension between them. Capacitor is used for allowing an AC (alternating current) to pass while a DC (direct current) is blocked.
Gautam
A motor travelling at 72km/m on sighting a stop sign applying the breaks such that under constant deaccelerate in the meters of 50 metres what is the magnitude of the accelerate
Maria Reply
please solve
Sharon
8m/s²
Aishat
What is Thermodynamics
Muordit
velocity can be 72 km/h in question. 72 km/h=20 m/s, v^2=2.a.x , 20^2=2.a.50, a=4 m/s^2.
Mehmet
A boat travels due east at a speed of 40meter per seconds across a river flowing due south at 30meter per seconds. what is the resultant speed of the boat
Saheed Reply
50 m/s due south east
Someone
which has a higher temperature, 1cup of boiling water or 1teapot of boiling water which can transfer more heat 1cup of boiling water or 1 teapot of boiling water explain your . answer
Ramon Reply
I believe temperature being an intensive property does not change for any amount of boiling water whereas heat being an extensive property changes with amount/size of the system.
Someone
Scratch that
Someone
temperature for any amount of water to boil at ntp is 100⁰C (it is a state function and and intensive property) and it depends both will give same amount of heat because the surface available for heat transfer is greater in case of the kettle as well as the heat stored in it but if you talk.....
Someone
about the amount of heat stored in the system then in that case since the mass of water in the kettle is greater so more energy is required to raise the temperature b/c more molecules of water are present in the kettle
Someone
definitely of physics
Haryormhidey Reply
how many start and codon
Esrael Reply
what is field
Felix Reply
physics, biology and chemistry this is my Field
ALIYU
field is a region of space under the influence of some physical properties
Collete
what is ogarnic chemistry
WISDOM Reply
determine the slope giving that 3y+ 2x-14=0
WISDOM
Another formula for Acceleration
Belty Reply
a=v/t. a=f/m a
IHUMA
innocent
Adah
pratica A on solution of hydro chloric acid,B is a solution containing 0.5000 mole ofsodium chlorid per dm³,put A in the burret and titrate 20.00 or 25.00cm³ portion of B using melting orange as the indicator. record the deside of your burret tabulate the burret reading and calculate the average volume of acid used?
Nassze Reply
how do lnternal energy measures
Esrael
Two bodies attract each other electrically. Do they both have to be charged? Answer the same question if the bodies repel one another.
JALLAH Reply
No. According to Isac Newtons law. this two bodies maybe you and the wall beside you. Attracting depends on the mass och each body and distance between them.
Dlovan
Are you really asking if two bodies have to be charged to be influenced by Coulombs Law?
Robert
like charges repel while unlike charges atttact
Raymond
What is specific heat capacity
Destiny Reply
Specific heat capacity is a measure of the amount of energy required to raise the temperature of a substance by one degree Celsius (or Kelvin). It is measured in Joules per kilogram per degree Celsius (J/kg°C).
AI-Robot
specific heat capacity is the amount of energy needed to raise the temperature of a substance by one degree Celsius or kelvin
ROKEEB
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Source:  OpenStax, Mathematics grade 9. OpenStax CNX. Sep 14, 2009 Download for free at http://cnx.org/content/col11056/1.1
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