2006-10-04 15:34:52 · 7 answers · asked by rachidik2 1 in Science & Mathematics ➔ Engineering
It means that you have to use a force to change the speed of an object. The speed can't change by itself.
The heavier the object, the more force must be used to accelerate(or slow down, or change direction of movement) an object.
2006-10-04 15:39:36 · answer #1 · answered by Anonymous · 0⤊ 0⤋
There is more than one type of inertia. The most basic is the tendency of mass to resist change in translational (straight line) motion. Newton's Law (F = ma) shows that a larger mass will accelerate more slowly than a smaller one. For straight line motion, the inertia is simply the mass.
For rotational motion, things are a little more complex. When you spin something, the parts farther away form the axis move faster than the parts closer in. It takes more force (for rotation force is actually torque) to get bodies farther from the axis to accelerate. A property is defned for a rotating mass called the moment of inertia (I). It is a direct analog to mass in translational systems where the force becomes a torque (T) and the angular acceleration ia 'a'. Newton's law for rotational systems is then T=Ia. The moment of inertia is evaluated usung calculus to sum up all the infintesimal masses multiplied by the square of the distance from the axis.
The third type of inertia is used in mechanics of materials for determining stress and strain. It is called moment of inertia because the approach for determining it is very much like the moment of inertia above. The more proper name for this moment of inertia is the second moment of area.
2006-10-04 18:11:29 · answer #2 · answered by Pretzels 5 · 0⤊ 0⤋
ahem
velocity is not speed
you must apply an external force to change the velocity (speed or direction) of an object.
Without the application of an outside force, an object in motion will say in motion; an object at rest will stay at rest.
Friction with the atmosphere, or gravity, for instance, is an outside force, which is why if you throw a baseball it will eventually strike the ground. In outer space, said baseball would travel indefinitely, in the same direction and with the same speed [IE, the same velocity] until some force acted on it.
2006-10-04 15:42:42 · answer #3 · answered by bequalming 5 · 0⤊ 0⤋
Inertia is a property of mass that resists a change in velocity. Objects as rest tend to stay at rest, objects in motion tend to continue in motion.
Force must be applied to an object to change its velocity. The amount of force that is needed is related to the object's inertia.
Inertia is not simply mass, because you can have inertial resistance to rotational motion, not just linear motion.
2006-10-04 15:41:36 · answer #4 · answered by eric.s 3 · 0⤊ 0⤋
INERTIAL MECHANICS
Inertia: An "innate force of matter" that enables objects of matter to maintain static and dynamic existence.
Present physical theory offers no mechanical definition for the cause of an inertial property of matter. It is assumed that an object of matter is associated with a property of inertia, measured by units of mass, and no further definition is required. This non definition of an inertial property limits the ability of present physical theory to define matter and space. The following documents are an attempt to define the mechanical cause of inertia and the consequences of inertial existence.
2006-10-04 15:39:48 · answer #5 · answered by Delores B 2 · 0⤊ 0⤋
Mass and Inertia of physical objects, reflects the content of matter in it. Mass is the property of the object which expresses the matter when the object is stationary. Inertia is the same expression of matter when object is in motion.
Both are interlinked and I think that they should be treated as two faces of the same coin.
2006-10-04 18:25:42 · answer #6 · answered by natanan_56 2 · 0⤊ 0⤋
it means if a body be ar rest , remain at rest until a force make it moving and if it is moving , it will move until a force make it to stop.
2006-10-04 19:42:12 · answer #7 · answered by eshaghi_2006 3 · 0⤊ 0⤋