At the highest point of a projectile:

1. The vertical velocity is zero.
2. The acceleration is equal to gravitational acceleration (g), typically $9.8 \, \text{m/s}^2$ downward.

Would you like more details or have any questions?

Here are 5 related questions to deepen your understanding:

1. What is the horizontal velocity of a projectile at its highest point?
2. How does the angle of launch affect the time to reach the highest point?
3. What is the total time of flight for a projectile given its initial velocity and angle?
4. How can you calculate the maximum height reached by a projectile?
5. How does air resistance affect the motion of a projectile?

Tip: The horizontal component of velocity in projectile motion remains constant (ignoring air resistance).