Eli5 Why is force equal to mass multiplied by acceleration and not speed ?

Question

If a car moves consistently at 80 kmh and it weighs at 600kg, is it not generating any force? since you know, a=0, am I stupid or is Newton ?

In: 13

Answer 1

You have to generate force to keep a car moving at constant speed on Earth because of air resistance. Air resistance creates a force on the car so you must therefore apply a force to cancel it out.

If you were in space, then a car (or any object) moving at constant velocity wouldn’t be generating any force.