An object will move at constant speed until acted upon by a force.
It depends on your setting. If the net force on an object is zero than the object will move with a constant speed. It will also move with a constant speed (but not velocity!) if a force forces the object to move in a circular motion.
an external force acts on it, causing a change in its speed or direction.
If the forces acting on an object are balanced and the object is moving at a constant speed, the object will continue to move at that constant speed in a straight line. There will be no change in the object's velocity or direction of motion.
No, an object moving at a constant speed cannot be accelerating. Acceleration is defined as a change in velocity over time, so if the speed is constant, there is no change in velocity and therefore no acceleration.
An object can move in a circle at different speeds.
Constant speed is movement at a fixed (constant) distance per unit of time. The same amount of distance is covered by the object in the same amount of time at each measurement of that same interval. An example of an object moving at a constant speed might be an object in orbit. Something up their above the drag of the atmosphere will move at a constant speed, and will continuously move around the earth at the same speed. Note that velocity is speed with a direction vector. An object in orbit will have a constant speed, but its velocity will be constantly changing because it is constantly changing the direction it is moving.
Constant speed is movement at a fixed (constant) distance per unit of time. The same amount of distance is covered by the object in the same amount of time at each measurement of that same interval. An example of an object moving at a constant speed might be an object in orbit. Something up their above the drag of the atmosphere will move at a constant speed, and will continuously move around the earth at the same speed. Note that velocity is speed with a direction vector. An object in orbit will have a constant speed, but its velocity will be constantly changing because it is constantly changing the direction it is moving.
If the net force acting on an object is 0, then the object will move with a constant velocity. This means that the object will neither speed up nor slow down, but continue to move at a consistent speed in a straight line. This is described by Newton's first law of motion.
A mass
Yes, an object can move at a constant speed if the three forces acting on it are balanced, resulting in zero net force. The forces can cancel out each other's effects, allowing the object to maintain a constant speed.
In that case, the object is said to move at constant speed.
No, most objects do not travel at a constant speed. Factors like forces acting on the object, changes in direction, and external influences can cause an object's speed to vary. Objects may speed up, slow down, or change direction as they move.