1. **Problem statement:** A crossbow bolt is shot straight upward with an initial velocity of 288 ft/s. We want to find the time it takes for the bolt to reach its highest point. 2. **Formula used:** The velocity of an object under gravity is given by $$v = v_0 - gt$$ where $v$ is the velocity at time $t$, $v_0$ is the initial velocity, and $g$ is the acceleration due to gravity (32 ft/s² downward). 3. **Important rule:** At the highest point, the velocity $v = 0$ because the bolt momentarily stops before falling back down. 4. **Set velocity to zero and solve for $t$:** $$0 = 288 - 32t$$ 5. **Rearrange to find $t$:** $$32t = 288$$ $$t = \frac{288}{32} = 9$$ 6. **Interpretation:** It takes 9 seconds for the bolt to reach its highest point. **Final answer:** The bolt reaches its highest point after $\boxed{9}$ seconds.