Force analysis diagram of the object in the equator! Force analysis of the equatorial object!

By gravity and centripetal force
All point to the center of the ball

Senior one physics: how to analyze the direction of several forces and resultant forces on an object? It's the content of Newton's second law of compulsory one. Solve it

The methods of analysis were as follows
1. Draw gravity first
2. Draw the contact force again
3. Finally, draw the force that doesn't touch
Note: when drawing a force, in addition to drawing the opposite side, it should also be said: the object receives a force (name of the force) given to it by an object (the letter indicating the force)

Physical stress analysis of senior one If a force of 600N is applied to the right side of a spring and a force of 600N is applied to the left side, the elongation of the spring is 600 / K. if a force of 700n is applied to the left side, which side of the force should be used for calculation? Why? 2. When a person stands on an elevator and makes a uniform acceleration movement, the acceleration is inclined downward along the elevator direction. Then why is the friction force in the horizontal direction? Why is not the friction force in the oblique direction opposite to the acceleration? Is the static friction force opposite to the direction of human motion

One
If a spring is subjected to a force of 600N on the right and 600N on the left, the elongation of the spring is 600 / K
If a force of 700n is given to the left side, the spring tensile force is considered as 600N, and the deformation is still 600 / K
Because the force on the spring stretching is the pull force F1 on the smaller side, the difference between the pull force F2 on the larger side and the pull force F1 on the smaller side f2-f1 provides acceleration for the whole spring: a = (f2-f1) / m
Two
A person standing on the elevator downward to do uniform acceleration movement, the acceleration along the elevator direction inclined downward
Because the steps of the elevator itself are parallel to the horizontal plane, people stand on this step and analyze the object by human beings. People are subjected to three forces: 1
Gravity mg, vertical downward;
The support force of elevator steps to people is n, vertical upward;
The friction force of elevator step to human is parallel to the step
The direction of friction is consistent with the tangent direction of the contact surface. The tangent direction between the person and the elevator step is horizontal, so the friction force can only be horizontal
In this paper, the forward friction force produces the forward horizontal partial acceleration: F = max;
The difference between the support force and gravity produces vertical acceleration: mg-N = may
[isn't the direction of static friction opposite to that of human motion]
There is no problem with this point. Because in this question, the relative movement trend between people and elevator steps happens to be horizontal and backward. The key is that you should notice that the steps are horizontal
In other words, if there is no horizontal step, if a person is standing on the slope, the direction of friction is the same as the slope, there is no problem

As shown in the figure, under the action of constant force F with mass m = 4kg, under the action of constant force F with an angle of θ = 37 ° to the horizontal direction, the small object starts to move uniformly to the right from stationary, and the dynamic friction coefficient between the small block and the horizontal ground is μ = 0.5. After TL = 2S, the constant force F is removed, and the small block continues to move forward, T2 = 4S, and then stops (1) The magnitude of constant force F; (2) The total displacement of small block X

(1) Let the acceleration of the object before the force F is removed is A1, and the velocity of the object at the end of T1 second is v. according to Newton's second law, we can get: fcos θ - μ (mg fsin θ) = MA1. From the kinematic formula: v = a1t1, the acceleration of the object after the force F is removed

Find all formulas of sine cosine theorem

Sine theorem: A / Sina = B / SINB = C / sinc
Deformation: 1. A: B: C= sinA:sinB :sinC
2、a=2RsinA b=2RsinB c=2RsinC
Cosine theorem: A ^ 2 = B ^ 2 + C ^ 2-2bc cosa is the same as B ^ 2 C ^ 2

Formula of sine and cosine theorem

a/sinA=b/sinB=c/sinC
a2=b2+c2-2bccosA

What is the formula of cosine theorem?

Cosa = b square of 2BC + square of C - square of a

If the three sides of a triangle are a, B, C, how can we determine that the triangle is an obtuse angle triangle?

1. Find out the longest side. Let's set it as C
2. Judge whether C ^ 2 > A ^ 2 + B ^ 2 is true
If the above inequality is true, it is an obtuse triangle; otherwise, it is not an obtuse triangle
(furthermore, if C ^ 2 = a ^ + B ^, it is a right triangle; if C ^ 2 < A ^ + B ^, it is an acute triangle.)
Note: x ^ 2 is the square of X

In the case of right triangle and obtuse triangle, the theorem of perpendicular center is proved

It is known that: 1) in RT △ ABC, C = RT ∠, 2) obtuse angle △ ABC, ∠ ACB > RT ∠,
It is proved that the heights of the three sides of △ ABC intersect at one point
It is proved that: 1) in RT △ ABC, AC ⊥ BC and BC ⊥ AC are CD ⊥ AB at point D, then the high AC, BC and Cd on the three sides of △ ABC intersect at a point C;
2) In the obtuse angle △ ABC, make ah ⊥ BC at D, BH ⊥ AC at e, ah crossing BH at point h, making a straight line ch intersecting AB at F,
 CDH = ∠ CEH = RT   CDH = ∠ CEH = RT ∠, the quadrilateral cdhe is inscribed in a circle,
DCH = ∠ DEH, i.e. ∠ AHF + ∠ DEH = RT ∠,
∵ ADB = ∠ AEB = RT ∠, quadrilateral adcb is inscribed in a circle,
﹤ DEH = ∠ HAF, i.e., ﹣ AHF + ∠ HAF = RT ﹥ HF ⊥ AB,
In other words, the high ad, be and CF on the three sides of △ ABC intersect at a point H

Tell you the length of the three sides of an obtuse triangle. How to find the height of an obtuse triangle?

The cosine of the adjacent corner of the base is obtained by cosine theorem
For example, cosa = (B? + C? - a?) / 2BC, Sina = √ [1 - (COSA) ˆ 2]
Then the height on B edge = C * Sina
Height on edge C = b * Sina
Suppose that the inner height is h and the three sides of the triangle are a, B, C (C is the largest side)
Then √ (a 2 - H 2) + V (B 2 - H 2) = C, i.e., √ (a 2 - H 2) = C - √ (B 2 - H 2)
If both sides are squared at the same time, we can get: a? H? 2 = C? - 2C √ (B? H? 2) + B? H
In other words, 2C √ (B 2 - H 2) = C 2 + B 2 - a 2
If both sides are squared at the same time, the result is: 4C? B? - 4C? H? = (C? + B? - a?)
That is (2cb-c? - B? + a?) (2CB + C? + B? A?) = 4C? H
∴ h=√[(a-b+c)(a+b-c)(b+c-a)(a+b+c)]/(2c)

Force analysis diagram of the object in the equator! Force analysis of the equatorial object!