A ball is thrown straight up, when it reaches the maximum height x, a second identical ball is thrown up with the same initial velocity as the first one. Where will these balls meet.

To determine the point where the two balls will meet, we need to use some basic kinematic equations. Let's break it down step by step:

1. Start by considering the motion of one ball. When it is thrown straight up, its initial velocity is positive (upward) and its final velocity, when it reaches the maximum height, is zero. The acceleration acting on the ball throughout its motion is the acceleration due to gravity (9.8 m/s^2), which is always directed downward.

2. Knowing that the value of acceleration is a constant (-9.8 m/s^2) and the initial velocity (upward) is positive, we can use the equation of motion to find the time it takes for the ball to reach its maximum height (x).

The equation we can use is: v_f = v_i + at, where v_f is the final velocity (zero), v_i is the initial velocity, a is the acceleration, and t is the time.

Plugging in the values, we have 0 = v_i + (-9.8)t.

3. Rearrange the equation to solve for the time, t: t = v_i / 9.8.

This equation gives us the time it takes for the first ball to reach its maximum height (x).

4. Now, since the second ball is thrown with the same initial velocity as the first ball, it will also take the same amount of time to reach the maximum height (x) using the equation we derived in step 3.

5. At the time both balls reach the maximum height (x), they will meet. However, since it is given that the motion is symmetric, the meeting point will be the midpoint between the two balls' starting positions.

Therefore, the meeting point will be located at half the maximum height (x) above the initial position from where the balls were thrown.

To summarize, the two balls will meet at a point located halfway between the initial position and the maximum height (x) that each ball reaches.