Explanation for Question 10 From the Math (Calc) Section on the 2017 May Sat
For question 10, they give us a graph and then they say a ball 2 was dropped from a height of 1.5 meters and hit the ground. 3 Several times. The graphic bulb represents the height and age and 4 meters of the ball T seconds after it was dropped of the following, 5 which best approximates the maximum height in meters of the ball 6 between the second and third time it hits the ground. 7 So that's key right there. Second and third. 8 And we're going to have to determine which where we're at on the graph, 9 um, to be between the second and the third. 10 So let's just really quickly look at the graph. 11 The first thing we do when we look at a graph or to read 12 a graph is we read the title. It says height of a ball, 13 then the x-axis and the y-axis, which say time for X and height 14 for Y um, 15 there's no key here. 16 So that would be the third step, but we don't have it. 17 Now we just draw conclusions from this graph. 18 We know they dropped it from a height of 1.5. 19 So imagine you have a ball in your hand and you drop it. 20 And then at height, zero and time, 21 just over 0.5. That's when it first touches the ground because the height is 22 zero. So it means it's at the floor. Then it bounces back up again, 23 reaches its maximum height, maximum height here and touches the ground for the 24 second time. And then again, 25 and touches the ground for the third time. So we want to know 26 the maximum height, um, 27 between the second and third time it hits the ground. 28 So this is the second and this is the third. 29 So we want to know the maximum height between this, 30 um, these numbers are these this time and that's going to be right here 31 by just looking at the graph. We just clicked. We would just select or 32 look at the maximum value. 33 And if we look, that's going to be about 0.4 meters, 34 which is B.