Physical optics mapping in grade two One night Xiao Ming was watching TV. He saw fireworks in the distance through the glass window. Xiao Ming wanted to watch it. His mother said it was too far away. Can you measure the distance? 1. If you are Xiao Ming, can you measure the distance? 2. Your experimental equipment 3. Your design 4. Detailed description 5. The physics knowledge you use

Equipment: stopwatch
Methods: see the fireworks immediately start timing, and so on to hear the sound of fireworks, press the Stopwatch Stop key
340 * stopwatch time is distance
(the speed of light is much higher than the speed of sound, negligible)
Physical knowledge: sound speed 340m / s, light speed 30000000 M / S

In the second year of junior high school physics, we drew circuit diagrams in series and in parallel. According to the actual circuit drawings, what good way can we draw them? How to distinguish the series and parallel connection in the physical picture? What's the good method? Specific point. Will pursue the point!

In the first figure, it is obvious that the left and right ends of the bulb are connected together (indicated by the red wire), then the circuit is regarded as parallel. On the contrary, as shown in Figure 2, the left and right ends of the bulb are not connected together, but a wire runs through two from left to right

It's very simple to draw the physical diagram according to the circuit drawing and to draw the circuit diagram according to the actual object drawing. What is the method of drawing the circuit diagram according to the requirements? For example, there are two lights, three switches, the first switch is closed, the two lights are not on, the first two switches are closed at the same time, and the first light is on,

First build the skeleton, then the meat
First of all, there must be a circuit to make the light on. You can draw a battery and an electric lamp, and connect them with wires to form a circuit;
Secondly, when the first switch is off, the two lights are not on, indicating that the switch is on the main circuit;
Thirdly, if the main circuit is connected (the first switch is closed), the second switch is also closed, and the lamp of the first station is on, the second switch is on the first branch
The key is to do more questions, their own careful experience

3. There are five kinds of optical elements: A, flat mirror; B, concave mirror, C, convex mirror; D, concave lens; E, convex lens. Please judge the light that should be selected for the following equipment

Just done: a C D B e c

To deflect the light as shown in the figure, the optical element () A. It must be a flat mirror B. It must be a convex lens C. It must be a concave lens D. Plane mirror, convex lens and concave lens can be used

It can be seen from the light path diagram below that plane mirror, convex lens and concave lens can change the direction of light
Therefore, D

Does science draw arm of force with broken line or solid line

A solid line is a dotted line only if the direction of the stretching force is drawn

Is the axis of symmetry of an axisymmetric figure a solid line or a dotted line

There are 3, 1. It's not a real line. It's because people can easily find out the symmetry point to make a figure. It's OK to draw a straight line or a straight line with the axis of symmetry of a line. It's not intentional

Is the auxiliary line added by mathematics a dotted line or a solid line For example, geometric connection, height, extension, etc. use solid line or dotted line? Please list them in detail, The teacher said that the height is solid line, please professional answer

If it's a proof question, the auxiliary line needs to use a dotted line. If it's a regular exam (I mean the kind of exam that will be arranged above grade), no matter what it is drawn, as long as it is a auxiliary line, it should be dashed. But if it is a drawing problem, it should use a solid line
PS: if it's just a normal test, I suggest you use what your teacher said, otherwise you will be scolded

Is the height of a cylinder represented by a dashed line or a solid line? In addition, this question in the PEP sixth grade volume two small number one, I do not express clearly. If you can take a look at it for me, Two cylinders that are as like as two peas, represent the line by H, and a high line with a dotted line. A high solid line is used to judge whether the two heights are correct.

If it is drawn inside, it should be dashed; if it is outside a cylinder, it can be solid

If you do a refraction map of light, do you use solid lines or dotted lines to reflect light?

Solid line should be used. Because as long as it is a real line, it should be a solid line. If it is an auxiliary line, it should be a dotted line, such as normal