If you are good at physics, please help, if you are good at physics, please help

Haha, that's the right question.

Electricity is actually very easy to understand, so I won't talk about the concept.

The concept of series, parallel. Pathway, open path. The concept of short circuits.

Especially the concept of short circuits, the diagram of short circuits is very tricky, but just keep one thing in mind. As long as there is a wire and the electrical appliance in parallel, it constitutes a short circuit, when the circuit flow direction, you can see that if the wire is only connected in parallel with the electrical appliance, the electrical appliance will be short-circuited, if it is also connected in parallel with the power supply, then the whole circuit will be burned.

There are a few more formulas to remember.

and its derivative formula.

I'm also a junior high school student.,It's just that I don't read it after a quarrel with the teacher.,Now I'm playing at home.,If you don't understand it.,Then you can add mine.。

Or e-mall: wolf

Look at the circuit diagram.

If there is an electric meter, cut it first, and when the ammeter is a wire, the voltmeter simply does not look at that part of the wire.

Look patiently along the positive electrode to the negative electrode (let's look at the simple ones first).

You'll understand.

It's very simple, don't think too much, I'm also studying here, I understand, it's okay, our teacher said, the final exam magnetism is the most important.

Master the law, Joule's law, etc.

It's simple, don't worry.

Hehehe!

To put it mildly: find patterns. Find a tutor. Don't talk about a lot of questions.

Do more questions. There is no other way.

Understand more, find out the connection between the knowledge points, and it is best to form a line of electrical knowledge.

Read more textbooks. Watch it several times. Then just start with a simple question.

Read the book a hundred times, and the meaning will come to you.

Find a pattern! Understand textbooks.

Specialized exercises are made.

When I was learning electricity, it was like looking at flowers in things, and I could only do more questions.

Let go of yourself, get rid of the psychological fear of physics first, do the simplest and most representative questions first, and be sure to understand the concept.

I think it should be c

The reason is that when water drops into the oil, it will boil rapidly, and the resulting water vapor bubbles will float until the oil surface bursts, resulting in sound and oil splashing.

cSince the temperature of the oil is much greater than the boiling point of water, when the water drops into the oil, the water bursts.

Due to the high density, if the water is poured into the pot, it will be in the lower layer of the oil, and the high temperature will make the water evaporate into a gaseous state, and the oil will bloom when the oil is lifted.

Choose C, reference only.

The boiling point of water is lower than the temperature of hot oil.

So the oil did not boil, and the water boiled and splashed out.

So let's choose C

The leftmost is m1, the first one on the right is m2, the second is m3m1, m2, and the acceleration of m3 is a1, a2, a3m1-t1=m1a1

t1=m1(g-a1)

t2=t1/2

a2=g-t2/m2

a3=t2/m3-g

a2=a3t2=2m2m3g/(m2+m3)=2*

t1=2t2=2g/15

2g/15=m1(g-a1)

a1=g/3

a2=a3=t2/m3-g=g/3

I've seen this question, if I'm not mistaken, it's the exercise that follows the first chapter of the sixth edition of General Physics

Answer: w useful = gh = 200n , = 50%.

From =w useful w total 100%, 50%=40j w total, from which we get w total=80j, and then w total=fs, f=w total s=80j (4 finally from p=fv v=p f=60w 100n=.

Hope it helps, thank you!

gh=fs×50%

f=g/（4×50%）=100n

Since p=w t=f v, the rope free end movement velocity v=p f=60w 100n=

h=1 2gt2 i.e. t=2h under the root sign g=under the root sign (in the case of g=10).

It's all about the basics, and you have to work hard to study in the future.

1. Floating and sinking conditions of objects:

1. Gravity and buoyancy.

2. Sinking, floating, suspending or floating.

Second, the application of floating and sinking conditions:

1. Density of liquids Buoyancy is equal to gravity.

2. Buoyancy is greater than gravity Float floating.

Buoyancy is less than gravity to sink.

3. Change your own gravity.

4. The volume of the gas.

Functional relationships need to be established.

The smaller the <>, the greater the COS, and the smaller the OA = Q2 + P2 - 2QPCOS) and the smaller the F.