Acceleration takes place the first 0-30 meters or to about 3-4 seconds from the start of a sprint. After approximately 30 meters acceleration turns into maximum velocity and top speed is hit.
In science, a hypothesis is an idea or explanation that you then test through study and experimentation. Outside science, a theory or guess can also be called a hypothesis. A hypothesis is something more than a wild guess but less than a well-established theory. In science, a hypothesis needs to go through a lot of testing before it gets labeled a theory. In the non-scientific world, the word is used a lot more loosely.
A hypothesis is a statement of the expected results of your research. A hypothesis states your guess as to the cause and effect that you expect to find (how one variable will affect another variable). Variables are merely things that can change (vary). Hypotheses are typically (but not always) stated in IF-THEN form.