Premise: "Onlookers watch a white stock car that has smoke coming out of the back."\nHypothesis: "There is a car race going on."\nDo we know that the hypothesis entailed by the premise?
Let's think step by step below.
it is not possible to tell
The car race may not be going on any longer since it appears there may be a crash.

.

So, the final answer is it is not possible to tell