Describe a situation in which the net external force on a system is not zero, yet its speed remains constant. And describe a system having a nonzero velocity while the net external force on it is zero. Describe such a situation
Answers
Newton’s second law of motion is closely related to Newton’s first law of motion. It mathematically states the cause and effect relationship between force and changes in motion. Newton’s second law of motion is more quantitative and is used extensively to calculate what happens in situations involving a force. Before we can write down Newton’s second law as a simple equation giving the exact relationship of force, mass, and acceleration, we need to sharpen some ideas that have already been mentioned.
First, what do we mean by a change in motion? The answer is that a change in motion is equivalent to a change in velocity. A change in velocity means, by definition, that there is an acceleration. Newton’s first law says that a net external force causes a change in motion; thus, we see that a net external force causes acceleration.
Another question immediately arises. What do we mean by an external force? An intuitive notion of external is correct—an external force acts from outside the system of interest. For example, in Figure 1(a) the system of interest is the wagon plus the child in it. The two forces exerted by the other children are external forces. An internal force acts between elements of the system. Again looking at Figure 1(a), the force the child in the wagon exerts to hang onto the wagon is an internal force between elements of the system of interest. Only external forces affect the motion of a system, according to Newton’s first law. (The internal forces actually cancel, as we shall see in the next section.) You must define the boundaries of the system before you can determine which forces are external. Sometimes the system is obvious, whereas other times identifying the boundaries of a system is more subtle. The concept of a system is fundamental to many areas of physics, as is the correct application of Newton’s laws. This concept will be revisited many times on our journey through physics.
Mark me as brainlist
Answer:Hey!!
Explanation:1) Describe a situation in which the net external force on a system is not zero, yet its speed remains constant.
Ans- A ball at the end of string traveling in a circular path at a constant speed. There would be a net external force on the ball pointing toward the center of the circle. The ball is acceleration because the direction of its velocity is constantly changing.
2)And describe a system having a nonzero velocity while the net external force on it is zero.
Ans- When you have a net external force of zero, that means that you are not accelerating. So when you have a non-zero velocity, and a net external force of zero, that simply suggests that you are travelling at a constant velocity and not accelerating.
3)Describe such a situation.
Ans-An object being pushed across the floor at constant velocity.
If you are satisfied with my Answer, please mark me as brainlist.