Answer:
An equation is needed to evaluate h(0).
When you evaluate h(0), you find the y-intercept of the graph because the independent variable inside the brackets, probably x or t, equates to 0.
The problem is needed for its context to be explained.
Although in most math problems, when h(x) form is used, h usually represents height.
I assume h(0) is the initial height, maybe the height that the rocket was launched or the height that the person who threw the ball is.