Senior 1 Physics 2nd Curriculum Reform, Senior 1 Physics Chapter 1 New Curriculum Reform

1.If a particle moves in a straight line with uniform variable speed, the velocity is va when it passes through point A, and the velocity is vb when it passes through point B, then the velocity when it passes through the midpoint position in the middle of AB is The velocity at which it passes through the middle of AB is

2.The initial velocity of the train braking 20m s is a uniform linear motion with variable speed, and the displacement passed in the 3rd s is 15m, then the acceleration of the particle motion is the displacement of the particle passing through 12s is m?

2v1*v2)/(v1+v2)

v1+v2)/2

100m Intermediate Position Speed:

v=x/t(2x)/[t1+t2]

2x)/[(x/v1)+(x/v2)]

2v1v2)/(v1+v2)

Intermediate Moment Speed:

v=x/(2t)

v1*t+v2*t)/(2t)

v1+v2)/2

Addendum: Calculate the average velocity first: v=x t=15 1=51m s

The average velocity is equal to the instantaneous velocity of the "intermediate moment".

That is, the speed of time.

From the beginning to, a=(v-vo) t=(15-20).

Then calculate the total displacement: x=[(vo+v) 2]*t=[(20+0) 2] 10=100m

Solution: Let the height of each step be xm and the number of steps be l.

Explanation: The actual speed of the rise of man, 42x the time of the rise of man, the speed of time = distance, the same is true for the right), the solution is u=

After 42x explains: lx 6 is the time for the human ascent, 42x is also, again, 48x instead of 42x is fine), and finally the solution is l=168

Answer: The actual number of steps from the first floor to the second floor is 168, the elevator speed u is the solution idea, 42x and 48x are the difference between any elevator, as long as the relevant quantity is found, the equation is listed, and the unknown quantity is contacted.

⊙o⊙)…I haven't read a physics book in years.

The gravitational force of the Sun on the Earth (learned in the chapter on the Law of Gravitation) provides the centripetal force of the Earth to move in a uniform circular motion, which produces centripetal acceleration and is always directed towards the center of the Sun sphere with a magnitude of f=gmm r2, and the gravitational force only changes the direction of the velocity, not the magnitude of the velocity.

The gravitational effect of the sun on the earth, gravity, gmm r, is directed towards the sun by the center of the earth's sphere, changing the direction of the earth's motion.

Physics is really difficult, but as long as you concentrate and work hard, you can still do it.

As long as you work hard, everything is simple.

It's so difficult.,I can't learn it.,I have to make up for it.。。。