Urgent Counseling !! How to exercise!!!

Go to the gym and let a professional trainer teach it, here, it can only be on paper.

Solution: (1) Take rod OA as the research object. The main power is a main power couple acting on it.

The rod ba is a horizontal two-force rod, so f ab is a horizontal force; o is a fixed hinge support, according to the force couple can only be balanced with the force couple, so the force fo and f ab form a force couple, that is, fo = f ab, the direction of the force fo and f ab is shown in figure b. Column equilibrium equations.

mi＝0， －m1＋fab×oasin30º＝0 fab=5kn

Fab = F Ab, its magnitude Fab = F Ab = 5kN, the direction is shown in Figure C; From the two-force equilibrium condition, f ba= fab, its magnitude f ba=fab=5kN, and the direction is shown in Figure C.

3) Rod O1b was taken as the research object. The main power is a main power couple acting on it. FBA= F Ba, O1 is a fixed hinge support, according to the couple, it can only be balanced with the couple, so the force FO1 and FBA form a couple, that is, FO1 = FBA, as shown in Figure D.

Column equilibrium equations.

mi＝0， －fab×o1b+ m2＝0 m2=

Thinking hard (meditating).

Quietly meditate (meditate).

Think well (think out).

Thinking confused (cranky).

Thinking very much (thinking about it).

Thinking a lot (thinking left and right).

Thinking ridiculously (wishful thinking).

Thoughtfully bizarre (whimsical).

I thought about it and thought about it (I thought about it for a while).

The toughest hair (one in a thousand).

The toughest argument (Great Argument Jona).

The most sincere apology (guilty of guilt).

The most urgent mood (anxious).

The toughest defense (impregnable).

The smartest investment (a million profits).

Widest field of view (unobstructed).

The worst reputation (10,000 years of retention).

The best memory (unforgettable).

The poorest land (no grass).

The smallest place (the land of projectiles).

The most astute person (improvised).

The best person (standing out from the crowd).

The loneliest person (alone).

If it is 3 and 3/5, then the three scores are (3 2), 9 10, and 6 5

Beat one's brains.

Turn something over in one's mind. Think about it.

Jump the track. Have one's head in the clouds.

Imagination.

（1）na2co3+bacl2=baco3↓+2nacl,（2）mgso4+2koh = mg(oh)2↓+k2so4

3) Do not react.

4) Do not react.

5) CaCO3+2HCl==CaCl2+H2O+CO2 (6)Cu(OH)2+2Hno3=Cu(NO3)2+2H2O(7) does not react.

8) Not reacting.

9) Mg(OH)2+2HCl=MgCl2+2H2O(10) does not react.

(1) Let the length of the rectangle be x, and the width is 4x 5

625 open root number = 25cm

x*(4x/5)=480

x*x=600

x = less than 25cm

Therefore, it is possible to cut out a rectangle that meets the requirements.

2) Length = 25cm

Width = 4 * 25 5 = 20cm

Area = 25 * 20 = 500 square centimeters.

EF AB, ABC EFC, BAC FEC and de BC, ABC ADE, quadrilateral DBFE is a parallelogram.

ade∽△efc，db＝ef，de＝bfad:db＝3:2∴ad:ef＝3:2∴ae:ec＝3:2，de:fc＝3:2

ac＝6∴ae＝，ec＝

fc＝2∴de＝3