4 A supermarket uses plastic carrier bags. 7 The handles of some of a new set of bags break when customers carry their shopping away. The supermarket complains to the company that makes the bags. The company tests 5 of the new set of bags. They find the mass that will break each bag. Here are their measurements. Bag number 1 2 3 4 5 Mass to break handle in kg 6.5 8.2 6.1.2 9.0 (a) (i) Use all their measurements to find the mean value of the mass to break the handles. Show your working.... kg [2] What is the range of these measurements?... to... kg [1] (iii) Measurements on older bags have the same mean value. The range for the older bags is 7.4 to 8.6 kg. Use this information and your answer to part to suggest why some of the new bags are breaking more easily than the old ones....... [1] OCR 2014 Turn over
(c) The company decides that the plastic they have is too flexible and has too large a range of flexibility. Technicians test small pieces of three other plastics. All the samples used have exactly the same size. They measure how far each sample bends under the same conditions. Their results are shown in the table. Distance sample bends in mm Sample number 1 2 3 4 5 6 mean Plastic A 35 33 35 34 34 33 34 Plastic B 14 13 14 15 13 15 14 Plastic C 18 12 14 17 13 14 Describe the advantages and disadvantages of each plastic for making fence posts. Which plastic would you choose and why? The quality of written communication will be assessed in your answer.... [6] [Total: 11] OCR 2013
8 4 A company decides to make fence posts from a plastic. The company makes and tests 0 fence posts with the same size and shape. They measure how far each post bends under the same conditions. The bar chart shows their results. 25 20 number of posts 15 5 0 0 1 2 3 4 5 6 7 8 9 11 12 bend in cm (a) (i) In the test, how many posts bent 9 cm or more?... [1] The company wants to make 500 posts each day. They will not sell posts that bend 9 cm or more. How many posts will they reject each day? Show your working. number of posts rejected =... [2] OCR 2013
8 3 A company plans to make a new rope for sailing boats. The new rope must be strong and quite stretchy. Scientists working for the company test ropes made from five polymers, A, B, C, D and E. They want to know which is the best polymer to use. They measure how much each rope stretches as a load is applied to it. They do this until the rope breaks. Each rope has the same thickness and the same length. Their results are shown in the graph. Each line ends when the rope breaks. 60 A 50 40 B C stretch in cm 30 20 D E 0 0 500 00 1500 2000 mass in kg 2500 3000 3500 4000 (a) Each rope must have the same thickness and length to make it a fair test. Explain why.... [2] OCR 2012
(b) Use the graph to decide which of these statements are true and which are false. Put ticks ( ) in the correct boxes to show your choices. 9 True ( ) False ( ) None of the polymers stretch. The polymer that supports the biggest mass breaks at 3000 kg. All of the polymers can support a mass of 1500 kg. The polymer that supports the biggest mass stretches the least for a mass of 1500 kg. [2] (c) (i) All five lines on the graph show the same pattern. Finish this sentence to describe the pattern. As the mass..., the polymer stretches.... [1] The graph shows differences between the polymers. Give two differences. 1... 2... [2] (d) The company chooses to make the new rope from polymer C. Suggest why they use this polymer rather than any of the others.... [3] [Total: ] OCR 2012 Turn over