3. If a body is moving with constant speed, no net force is acting on it 4. Frictional force is a constant force which acts on a body.
5. Action-reaction forces cancel one another.
6. Gravitational force does not act in outer space.
7. Ball bearings convert sliding friction to static friction.
Answers
Answer:
3.An object with no net forces acting on it which is initially at rest will remain at rest. If it is moving, it will continue to move in a straight line with constant velocity.
4.Forces are "pushes" or "pulls" on the object, and forces, like velocity and acceleration are vector quantities. ... a is its acceleration.
5. exerted by two objects on each other are often called an action- reaction force pair. ... However, action and reaction force pairs don't cancel because they act on different objects. Forces can cancel only if they act on the same object.
6.Anything with mass creates gravity. The gravity generated by the Sun, Earth, the Moon, and other planets stretches throughout outer space. ... On Earth, astronauts feel the force of gravity as weight, because Earth's surface prevents them from falling. In outer space, however, there is no ground to push against astronauts.
7. So in machine parts, we use ball bearings to convert sliding friction to rolling friction in order to reduce friction between moving parts. This reduces heat and wear and tear, and increases the efficiency and life of the machine
Explanation:
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