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Anonymous users2024-02-07Anyway, you have to challenge authority.
We know that force is the cause of the motion of an object. Newton's first law says that if an object is not subjected to force or the net force is zero, then the object must move in a straight line at a uniform speed or be at rest. If we want to discuss it further, then we have to go back to the concept of acceleration.
We know that acceleration is the ratio of the amount of change in velocity to the amount of change in time, and when the change in velocity is 0, the acceleration is zero, that is to say, the resultant force is zero. Note: The velocity change is zero, which means that velocity is a constant.
Motion with constant velocity is a uniform linear motion or rest. You may want to ask why the circular motion at uniform velocity is not f=0, knowing that velocity is a vector quantity, and it has a direction. The velocity does not change, but the direction is not uniform.
Uniform circular motion is only the magnitude of the velocity is constant, and its direction is time-changing. Ask me if you don't know yet.
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Anonymous users2024-02-06Force changes the physical state of motion, whereas the motion of an object does not require force to maintain.
The force acts on the object and the effect is to produce an acceleration which can change the magnitude of the velocity and can also change the direction of the velocity. When the resultant force is 0, the sum of the accelerations produced by the various forces on the object is also 0 (because the direction of acceleration is the same as the direction of the force, the vector sum of the accelerations produced by several forces is also 0 when the vector sum of their forces is 0).
An acceleration of 0 means that the motion of the object will not change, and the object will remain at rest or at a constant motion.
And 1l is not right. Uniform circular motion refers to a uniform velocity and does not fall under the category of uniform motion.
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Anonymous users2024-02-05What's wrong with this? There's nothing wrong with that.
In any case, as long as it is moving at a uniform speed, the net force is zero.
Because, force is the cause of changing the state of motion of an object, while uniform velocity, i.e., the state of motion (magnitude, direction) does not change. So the resultant force is zero.
What's wrong with you? Or try to give a counter-example. But you can't find such a counterexample.
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Anonymous users2024-02-04I don't remember it clearly, it seems to be a bit of a problem, uniform circular motion, centripetal force is not 0, I can't remember clearly, forgive me if I answer wrong! When I was in high school, I thought I was going to add two straight lines, which I used to write.
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Anonymous users2024-02-03Wrong, 2 words missing.
Uniform linear motion f is equal to zero.
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Anonymous users2024-02-02According to Newton's second law, the acceleration of an object decreases first and then increases. Due to 0-t1
During this time, the direction of acceleration remains the same, and the direction of acceleration is always the same as the direction of velocity, so C is correct and A, B, and D are wrong
Therefore, c
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