Question

If a car weighing 1500 kg and a Truck weighing 4000 kg are both traveling at 55 miles per hour which one will take more Force to stop

Answer 1

The truck will require force to stop:

Force equals Mass x Acceleration (F = m * a)
Both vehicles will need to decelerate by 55 miles per hour, so the one with a greater mass, m, will require more force to stop. The truck has a mass of 4000 kg, which is greater than the car's 

Answer 2

The same amount of force can stop both the car and the truck. But it would take longer to stop the truck, because the truck has more mass, so the acceleration of the truck would be smaller.