Question

What is the mass of a car that weighs 140,000 N

Answer 1

Assuming the force the car exerts is 140,000 N and that the car is stationary on a flat surface. You can apply Newton's Second Law of Motion.
F = MA
Where the acceleration is gravity (-9.8m/s).
140,000 = M*-9.8
M = 14285.71kg