If the data supports the hypothesis, then we consider the hypothesis to be verified and true. If however, the data does not support the hypothesis or refutes it, then the hypothesis is in trouble, and we have to come up with a different hypothesis to explain the observations.

Are data that do not support a hypothesis useful?

If the data consistently do not support the hypothesis, then CLEARLY, the hypothesis is NOT a reasonable explanation of what you are investigating. The hypothesis is rejected, and we search for a new interpretation, an new hypothesis that supports the experimental data.

Do the data for the first part of the experiment support or?

The data for the first part of the experiment support the first hypothesis. As the force applied to the cart increased, the acceleration of the cart increased.