Challenge Level

Process | Graph | Equation | Explanation |

1 | 6 | H | In a food-limited environment bacteria tend to maximum number after initial exponential growth (following lag phase) |

2 | 5 | B | Concentration will exponentially decay as drug is metabolised |

3 | 9 | E | Pendulum will have an sinusodial motion with a decaying amplitude due to damping from air resistance |

4 | 7 | I | Ideal gas equation $pV = nRT$ therefore pressure and volume are in a reciprocal relationship |

5 | 2 | A | Ball is small and heavy, therefore assume air resistance is negligible at first and so acceleration is constant. $s = ut + \frac{1}{2}at^2$ therefore for $u=0;\ a=g \Rightarrow s=\frac{1}{2}gt^2$ (qualitatively vertical speed represented by gradient of graph is increasing) |

6 | 1 | F | As concentration of reagent increases so does reaction rate, however as increase continues concentration of the catalyst becomes the limiting factor (saturation) |

7 | 4 | G | When not food limited, bacteria follow exponential growth after initial lag phase |

8 | 3 | D | Hours of daylight varies from a maximum at mid-summer to minimum at mid-winter, with a mean value of 12 |

9 | 8 | C | Earth's orbit is not perfectly circular therefore small oscillations about mean distance (1 AU) with period of one year (note non-zero origin on vertical axis) |