Two idential train engines are parked on parallel track. one engine has ten cars attached and the other has no cars attached. each engine exerts the same net force. which allow sthe train to overcome static friction. which engine will be able to accelerate more

The second engine with no cars will accelerate more.

Explanation:

Since the engines are identical so they hacve the same mass. The first engine has 10 cars attached which adds more mass to it whereas second engine has no cars attached.

Therefore second engine is lighter in mass than the first one.

We know from the Newton's second law of motion:

Now, according to question both the engines exert same force for moving.

We see that :

So more is the mass, lesser is the acceleration, hence the second engine with no cars will accelerate more.

it is very well related to a lot of things but with my limited knowledge i can confidently say that the answer is space.

the independent variable, or the one that is intentionally manipulated is the speed.