What's the answer to this and why? Could someone explain please?
Urgent GCSE Maths question Watch
- Thread Starter
- 25-05-2016 22:19
- 25-05-2016 22:21
- 25-05-2016 22:23
You need to work out the volume of the prism first...work out the area of the trapezium then multiply by the length of the prism.
Then you'll work out the mass using the volume..
- 25-05-2016 22:25
Work out volume
Multiply by density
Convert to kilos
If you don't get it, look at the unit and see how they cancel
- 25-05-2016 22:29
- 25-05-2016 22:36
This is how my brother came about doing it, but it's incomplete because he doesn't know how to convert into kilograms.
1/2 (a+b) h Area of a trapezium
(8+12 divided by 2) 6
10 multiplied by 6= 60 cm
60 multiplied by 20= 1200cm
1200 multiplied by 5= 6000
- 25-05-2016 22:37
- I hope
- 25-05-2016 22:39
You first need to keep in mind the formula for the mass, which is mass = volume * density.
Now that you know that formula you need to find the volume and the density which has already been given to you 5 g/cm3.
To find the volume you do the area of the cross section * the length of the shape. You know that the area of the cross section is found by using the formula for the trapezium which is ((Base 1 + Base 2)*Height)/2. Therefore you do ((8+12)*6)/2 = 1200 cm3.
Now that you know the volume you can find the mass by doing volume * density, therefore 1200 * 5 = 6000 grams.
6000 grams = 6Kg
Your answer is 6 Kg.Last edited by MehdiK24; 25-05-2016 at 22:41.