Science Question- Laws of Motion?

Question

I'm doing my science homework and I honestly tried to find this answer but I just don't understand it, could someone help me? Here's the question:

An engine can exert a force of 1,000 newtons. How fast can this engine accelerate a:

a.) 1,000 kg car

b.) 2,000 kg car

Answer 1

F=m*a

they want you to find acceleration, a:

a=F/m

F=1000N

m= ? kg car