# Moment of inertia

1. Aug 1, 2010

### rajeshmarndi

can an object be released in space where there is no friction, to travel with a constant velocity as an force will always produce an acceleration.

as moment of inertia says if an object is flying with an velocity say 20m/s, it will continue to do so unless external force is applied.

2. Aug 2, 2010

### mathman

In theory, if there is no external force, it will travel at constant velocity. In practice there will always be gravity from all the objects (stars, planets, etc.) that are in space.

3. Aug 2, 2010

### mikelepore

The word "inertia" applies to this question. The term "moment of inertia" is something different, related to rotational motion, not linear motion.

4. Aug 2, 2010

### rajeshmarndi

what i want to ask is that in theory if a particle is applied force, it will always travel with constant acceleration proportional to the applied force.
So what has to be done to make an object travel with constant velocity in space ignoring other existing forces or gravity.

5. Aug 3, 2010

### mathman

If an object is moving with a given velocity and no forces are applied, it will keep moving at that velocity (Newton's first law).

6. Aug 3, 2010

### rajeshmarndi

my question is how one can make an object to fly with a constant velocity, bcoz to make an object move, an force is neccessary and a force will always make an object to either accelerate or deaccelerate.

7. Aug 3, 2010

### pallidin

I think mathman answered that precisely. Do you agree?

8. Aug 4, 2010

### fawk3s

The object keeps accelerating as long as force is applied. You stop applying force, the object will keep moving at constant velocity.