Here's why:
* The "a" in "rapid" is short. It makes the sound of "a" in "cat" or "hat".
* Long vowel sounds are typically associated with vowels that are followed by a single consonant and a silent "e" (like "ate" or "hope") or vowels that are part of a vowel digraph (like "ai" in "rain").
Let me know if you'd like to explore other words and their vowel sounds!