End of Unit Assessment Grade 10 – Chapter 21 (Ratio, rate and proportion) Name ………………………………………………….………………………. For Teacher’s Use Question 1 Additional materials: Ruler Calculator allowed READ THESE INSTRUCTIONS FIRST • • • Answer all questions in the spaces provided on the question paper. You should show all your working on the question paper. The number of marks is given in brackets [ ] at the end of each question or part question. The total number of marks for this paper is 29. 2 3 4 5 6 7 8 Total /29 1 1 Annette cycles a distance of 70 km from Midville to Newtown. Leaving Midville, she cycles for 1 hour 30 minutes at a constant speed of 20 km/h and then stops for 30 minutes. She then continues the journey to Newtown at a constant speed of 16 km/h. (a) On the grid, draw the distance–time graph for the journey. [3] (b) Calculate the average speed for the whole journey. ................................................... km/h [3] [Total: 6] 2 2 y is directly proportional to the cube root of (x + 3). When x = 5, y = . Find y when x = 24. y = ................................................... [3] [Total: 3] 3 The people who work for a company are in the following age groups. Group A Group B Group C Under 30 years 30 to 50 years Over 50 years The ratio of the number in group A to the number in group B is 7 : 10. The ratio of the number in group B to the number in group C is 4 : 3. (a) Find the ratio of the number in group A to the number in group C. Give your answer in its simplest form. .............................. : .............................. [3] 3 (b) There are 45 people in group C. Find the total number of people who work for the company. ................................................... [3] [Total: 6] 4 A car starts from rest and accelerates at a rate of 3 m/s2 for 4 seconds. The car then travels at a constant speed for 10 seconds. V Speed (m/s) NOT TO SCALE 0 0 4 Time (seconds) 14 The diagram shows the speed–time graph for this journey. (a) Find the value of V. V = ................................................... [1] (b) Calculate the total distance travelled by the car during the 14 seconds. ................................................... m [2] [Total: 3] 4 5 Tins of paint are filled at the rate of 2 m3 per minute. How many 750 ml tins of paint can be filled in 1 hour? Answer................................................... [3] [Total: 3] 6 F is inversely proportional to the square of d. Explain what happens to F when d is halved. .................................................................................................................................................................... [1] [Total: 1] 7 The force of attraction, F Newtons, between two magnets is inversely proportional to the square of the distance, d cm, between the magnets. When d = 1.5, F = 48. (a) Find an expression for F in terms of d. F = ................................................... [2] 5 (b) When the distance between the two magnets is doubled the new force is n times the original force. Work out the value of n. n = ................................................... [1] [Total: 3] 8 The following is a velocity-time graph over the course of 6 minutes. (a) Estimate the distance covered in the first 4 minutes. ………………………… m [3] (b) Is your answer to part (a) an overestimate or underestimate? Explain your reasoning. ………………………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………………………… [1] [Total: 4]