recreated in 2009. Assuming that the following table indicates the vertical height $h$ that the cannonballs dropped $t$ seconds after being released till it hits the ground and comes to rest.

Galileo's famous Leaning Tower of Pisa experiment demonstrated that the time taken for two balls of different masses to hit the ground is independent of its weight. It wastime $t$ | 0 | 0.5 | 1 | 1.5 | 2 | 2.5 | 3 |

height $h$ | 0 | 1 | 5 | 11 | 20 | 30 | 44 |

Which of the following is the best approximation for the **instantaneous speed** at $t = 2.5$?