Problems with Newton s First Law of Physical Forces.

That is, the geometric sum of all the forces exerted on the object is equal to zero.

Let's say an object is only subjected to a vertical upward pull and a gravitational force (certainly vertically downwards), and the magnitude of gravity is equal to the magnitude of the vertically upward pulling force.

This is called zero net force on the object.

The force experienced by an object in the horizontal direction is equal to the force in the vertical direction, which is a large inverse collinear.

That is, the object is either stationary or moving in a straight line at a uniform speed.

When all objects are not subjected to external forces, they always maintain a uniform linear motion or a state of rest.

All objects remain in a state of uniform linear motion or at rest until an unbalanced external force forces it to change this state. This is Newton's first law (the law of inertia).

Newton's first law can also be abbreviated as: the moving is perpetual, and the static is constant.

If two forces in opposite directions are on the same straight line, their difference should be 0; If they are not on the same line, they can be broken down into pairs of forces (each two in the straight direction) using the parallelogram rule, so that the sum of each two forces should be 0

If the net force is zero, it is in equilibrium. When you learn the synthesis of force in high school, you will naturally understand. Junior high school doesn't have to go deeper.

A net force of zero indicates that the object is under the action of a balancing force. All external forces cancel each other out. Then the resultant force is zero.

Newton's First Law in Junior High School:Any object should remain in a uniform linear motion or at rest until an external force forces it to change its state of motion.

Newton's explanation in the Mathematical Principles of Natural Philosophy is that any object must remain in a uniform linear motion or at rest until an external force forces it to change its state of motion. This expression has been cited in the high school physics textbooks of the People's Education Edition and the Cantonese Education Edition.

It is expressed mathematically as: where is the resultant force, v is the velocity, and t is the time.

The statement in the Lujiao version of the high school physics textbook is: Newton's first law shows that when the external force is zero, the original stationary object will continue to remain at rest, and the original moving object will continue to move in a uniform straight line at the original speed. The resultant external force is zero and includes two cases:

One is that all the external forces on the object cancel each other out, and the net external force is zero; The other is that the object is not acted upon by an external force. Some experts and scholars believe that this way of expression is not rigorous, so the original expression is usually used.

Scope of application:

Newton's explanation in the Mathematical Principles of Natural Philosophy is that any object must remain in a uniform linear motion or at rest until an external force forces it to change its state of motion. This expression has been cited in the high school physics textbooks of the People's Education Edition and the Cantonese Education Edition.

It is expressed mathematically as: where is the resultant force, v is the velocity, and t is the time.

The statement in the Lujiao version of the high school physics textbook is: Newton's first law shows that when the external force is zero, the original stationary object will continue to remain at rest, and the original moving object will continue to move in a uniform straight line at the original speed. The resultant external force is zero and includes two cases:

One is that all the external forces on the object cancel each other out, and the net external force is zero; The other is that the object is not acted upon by an external force. Some experts and scholars believe that this way of expression is not rigorous, so the original expression is usually used.

The positive pressure of the weight on the disc is exactly equal to mg when the disc falls to its maximum velocity.

Explanation: At this time, the acceleration of the weight is 0, and the resultant external force of the weight at this moment is 0, so the gravity of the weight and the support force at the bottom of the plate are balanced (the magnitude is equal and the direction is opposite), and the positive pressure of the weight on the disk and the support force of the bottom of the weight are a pair of action and reaction forces, and the total size is kept equal, and the equal amount is replaced, so that the positive pressure of the weight on the disk is exactly equal to mg.

Option C analyzes the weight, which is supported by gravity and upward, and the question requires that the support force is equal to mg (the pressure is equal to the support force).

When first released, the support force is zero.

The velocity is zero, that is, when the lowest point, it will bounce back upwards immediately, so the support force is greater than the gravity of the whole process, the support force changes from zero to large, until it is greater than the gravity, the speed becomes larger and then smaller, when the speed is maximum, the support force is equal to gravity.

c indicates that the resultant force of the weight is 0, the acceleration is 0, and the velocity is maximum.

d When the velocity is zero, the object is at rest, then it is a balanced force, and the pressure is equal to mg

d. The speed is zero, that is, it is stationary, and the force is balanced at that moment, pressure = support force!

m: mg=ma a= x1=at 2=5mm:f- mg=ma2 a2=f vertical collapse 10-1 x2= a2t 2=5m

Roll from the title bucket x2-x1=1

From this the remaining pin circle is f=40n

16n, the vertical number of slag answers to see the first picture of the remaining beam.

Answer: 1...The lower piece flies out, and the top piece falls to the position of the lower piece. The reason is that the lower piece changes its state due to the force, and the upper piece remains in its original state (meaning in the horizontal direction) due to inertia.

2.It shows that the egg has to maintain its original static state due to inertia, but when the cardboard is forced to fly out, it loses its support and falls into the cup.

3.(1) The purpose of choosing the "inclined plane" in the experiment is to make the trolley gain speed.

2) The distance of the trolley on the surface of different objects is unequal, which indicates that the distance of the trolley is related to the resistance of the plane.

3) The conclusion drawn from this experiment is that the rougher the plane, the greater the resistance and the smaller the distance of movement.

4) Further reasoning, if the surface of the object is absolutely smooth, the trolley will maintain its original speed and continue to move (as a uniform linear motion).

4.Fall back into human hands. Because before the throw, the ball has the same horizontal speed as the boat, after the vertical throw, the ball is not stressed in the horizontal direction, due to inertia, the ball is the same as the boat, and maintains the original speed in the horizontal direction, when the ball falls back, it is the same as the boat's horizontal distance, so the ball will fall back into the human hand.

Answer your first question first! 1 is knocked out and does not move 2 has inertia and the second !! 1. The purpose is to make the object have the power to move, 2. Explain that the obstruction effect is different, 3. Different objects hinder the movement of the object differently, 4. Keep moving.

1.Fly out and fall Reason: Inertia.

2.Everything has inertia.

3.(1) make the speed of the trolley the same when it reaches the plane (2) the roughness of the contact surface affects the distance of the trolley sliding.

3) The friction force is related to the roughness of the contact surface (4) The uniform linear motion is carried out all the time.

1.Knocked away, falling in place, the object has inertia.

2.Eggs have inertia.

3.Make the trolley fall on the horizontal plane with the same initial velocity, the resistance of the trolley is different, when the falling height is the same, the smoother the contact surface, the smaller the resistance, the farther the distance of the object movement has been doing uniform linear motion.

Hope it helps.

The law of ternary equilibrium: The process by which two non-equilibrium states tend to equilibrium in a system is the process of ternary equilibrium.