Which has greater inertia - a speeding car or a jet airplane sitting on a runway?
1 Answer
The jet airplane sitting on a runway will have greater inertia then a speeding car due to its larger mass.
Explanation:
The inertia of an object is its resistance to change its position if not in motion, or its resistance to changing its motion for a moving object. Inertia is a definition of mass so an object with greater mass will have greater inertia.
The mass of the engines of the airplane on their own probably have more inertia than the car. Mass is usually measured by determining the weight of the object, which is defined as the gravitational force pulling down on it.
When a mass is forced to change its motion, either from rest, or its direction, or its speed, it is accllerated. Since force is the product of the mass times accelleration, as the mass gets bigger, the force will also need to increase to result in a change of accelleration.
There are images and information here:
http://www.physicsclassroom.com/class/newtlaws/Lesson-1/Inertia-and-Mass
