In approximately 0.3 seconds it has covered half its range. The trajectory for projectile motion is symmetric about the point of maximum height. The projectile covers the same horizontal distance reaching its maximum height as it does falling from its maximum height back to the ground. It takes the projectile the same amount of time reaching its maximum height as it does to fall from the maximum height back to the ground. When the projectile reaches its maximum height, after approximately 0.3s, the vertical component of its velocity is zero.
Some problems involve the motion of two particles.
Often these problems require that the two particles meet at the same place at the same time. An often stated problem is the monkey problem. A zookeeper stands a distance d from the tree, with a banana in his hand. The zookeeper knows that the monkey always lets go of the branch just as the banana is thrown to it. If you want to step through the video frame by frame click here.