Reflection Frances

What I Learned…

Recently，i have learnt 2 units which are vector dynamics and equilibrium. In vector dynamics, it shows the force and friction.  vector dynamics along the direction perpendicular to each other two selected vector dynamics called force, the more total  force the use of vector dynamics  by algebra formulas to solve the vector .In the orthogonal decomposition of the force, the purpose of the decomposition of the force, and particularly suitable in the case of the object by a plurality of force, an object F1, F2..., seeking the force F, the various forces in mutually perpendicularde composition, x-axis, y-axis in the x-axis direction of the force component for F1x, F2X,  ... respectively, in the y-axis direction of the force component F1y, F2y, .... then the x-axis direction all force Fx = F1x + F2x +  ... in the direction of the y-axis of the resultant force Fy = F1y + the F2y of + .... all forceset up a joint force with the x-axis angle for θ, then. use orthogonal decomposition method problem solving, the key is how to determine theCartesian coordinate system, the statics, less resolving power and easily decomposed force principle; dynamics, acceleration and vertical acceleration direction to establish coordinate axis, so that Newton's second law of expression: F =ma

 

 

Difficulties...

Sometimes, i will confused with the sin and cos.Before i thought that Fgy equal Fn, actually it is not right.

 

 



When i do this kinds of questions, i don't konw how to slove the tension.

 

 

 

Problem-Solving Skills

 

The first step, the selected object of study and be represented in the form of the particle.
The second step, the force analysis of the selected object.
The third step is the establishment of a Cartesian coordinate system. Generally speaking, in the horizontal plane can be established on the coordinate system, but the best slant build the x-axis direction along the object decline, and then the establishment of the Y-axis.
The fourth step, the analysis of the acceleration direction. Necessary acceleration orthogonal decomposition, in order to do title.
The fifth step is to express aggregate of external forces.
The sixth step, lists the X-direction, and the Y direction on the Newton's second law equation.
Step Seven For other equations, but also to list the equation and then solve.
Step eight ,check it. (Such as the force of the negative undesirable)