If there are no forces acting upon the object, then there is no acceleration. If there is no acceleration, then the object will move with a constant velocity.
If an object is not accelerating, then zero net forces act on the object.
<u>Explanation:
</u>
As per Newton's second laws of motion, an object exhibiting acceleration is directly proportionate to the net forces act on the objects and inversely proportionate to the object's mass.
But object's mass cannot be zero, so if the acceleration is zero for an object, the total forces act on that object will be zero. And for zero net force to occur, two equal but opposite forces are enough to nullify the net force. Thus if an object does not accelerate, then zero net force acts on the object.
A machine can never be 100% efficient because some work is always lost
due to the lack of materials or equipment that would convert work by 100%. It follows
the second law of entropy. The ideal engine is known as Carnot’s engine having
a 100% efficiency. So far, no engine has ever gotten to 100%.
