Physics wh y is it easier to stop a lightly loaded ...

The heavier truck has more momentum, which is the product of the speed and the mass of an object. The more momentum an object has, the more difficult it would be to stop it. It's explained well on

The amount of force needed to stop a truck depends on two things:

1. The mass of the truck
2. How quickly you want to stop it, that is, by how much do you want it to slow down each second.

The mass of a heavier truck is larger than the mass of a lightly loaded one. Assuming that both trucks are moving at the same speed, and that you want to stop them within the same time, then you're going to need to apply more force directly in proportion to the difference in masses. For example, if the heavier truck is twice as massive as the lighter one, you're going to have to apply twice as much force to stopit in the same amount of time. Conversely, if you apply the same amount of force, it's going to take twice as long to come to a stop as the light truck.

This is due to Newton's second law of motion: F=ma. Here, F is the force, m is mass, and a is acceleration, that is, the rate of change in velocity (speed).

Note that the same applies for speeding up the trucks as well: It takes twice as much force to get the trucks to go from rest to, say, 50 miles per hour in the same amount of time.

seeker. 

An example: A moving object going at a certain speed will double its weight but will keep its mass if it suddenly tries to stop. So the heavier "weight" will take more energy to stop it. The object will try to keep on going ( it don't want to stop!) The principle ALSO applies when you try to push over a heavy object (lets say 150 lbs & you are 45 lbs) There is a math formula ( don't ask me!)  that says that u won't be able to push it over standing still, but if u run a long enough distance & fast enough your mass will stay the same, but your weight WILL increase and you will push over the heavier object.