These videos deal with density mass volume problems, and are aimed at around grade 5 GCSE maths. You’ll need to apply the formula: density = mass/ volume with most of the questions and, as before, please do stop the video, try the questions, and compare your solution.
1. The diagram shows a solid cuboid made of wood. The wood has a density of 0.56 grams per cm cubed. Calculate the mass of the cuboid.
2. The density of gold is 19.4 grams per cm cubed. A gold ingot is produced in the shape of a cuboid. The cuboid has length 20cm, width 8cm, height 2cm. Work out the mass of the gold ingot. Give your answer in kilograms
3. A solid cylinder is made of wood. It has a radius of 8cm and a height of 3cm. The cylinder has a mass of 392 grams. Work out the density of the wood. Give your answer correct to 2 significant figures.
4. Seawater has a density of 1.02g/cm3. 255g of seawater mixes with some freshwater, to form coastal water. The coastal water has a mass of 304.5g, and a density of 1.015g/cm3 . Find the density of the freshwater.
Here’s a link to the question: Quick test – Density mass volume
and here’s the answer paper: Quick Test Density mass volume ANSWERS – apologies for the fairly basic pdf – it might be better to watch the video 🙂
The questions appear in all the main GCSE exam boards – Edexcel, AQA, OCR and Educas. They are popular and, once you have the basic principles, fairly similar. Although question 4 on the second video, might be a little more challenging.
- Always write down the formula for each question, particularly when you are revising, as it will help you to remember
- Make sure the units are the same – cm³? m³? grams? kilograms?
- Sketch the question, if there are quite a few words
Here’s a slightly older post:
Please do leave a comment below if you are not sure. Alternately you can view my YouTube channel and leave a comment there – I’ll always try to respond as quickly as possible.
Watch these videos on YouTube: