What is the force???

Question

What is the unbalanced force acting on a moving car with a constant velocity of 21 m/s (47 mi/h)? 
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Answer 1

If the velocity is constant, then there is no acceleration and therefore no force acting on the car.  (Unless you want to account for friction, but since you didn't mention that at all or any way to figure it out, I'll assume you don't want to.)

 

So the force is 0

 

Answer 2

The answer is zero.  A body moving with constant velocity has zero acceleration and so zero net force.