Why should the antenna be set up away from the wires? Yellow mud water seed selection?

1. Why should the antenna be set away from the wires? What should I do if I set up a TV antenna at home and encounter thunderstorm weather?

A: Electromagnetic fields (electromagnetic waves) will be generated around wires or high-voltage lines, and the antenna will also receive electromagnetic signals. Being too close will cause interference.

It is a bit unrealistic for individual home users to install equipment that can completely protect against lightning. Therefore, in thunderstorm weather, do not use the outdoor antenna of the TV, but unplug the antenna, because once the lightning hits the TV antenna, it will be introduced into the room along the TV antenna, threatening electrical appliances and personal safety.

2. Yellow mud water seed selection? The standard of mud density is that eggs can be suspended in water, bamboo baskets filled with seeds are put into mud, and seeds are selected by stirring. Explain why?

A: Yellow mud seed selection is a method of seed selection, and salt water seed selection is also commonly used. The main principle is to make yellow mud water or salt water into a density similar to that of improved varieties (it can make eggs suspended in water \ and the density is close to that of eggs). Good \ bad seeds have different densities (specific gravity), and there will be differences between floating or floating or sinking in yellow mud water. Bad seeds are not full and have low density, so they will float on them. It's good.

3. Measure the strength of people from the bottom of the building to the third floor with the meter ruler of the watch, and write the measured physical quantities and expressions.

A: There seems to be one condition missing from the title, that is, people's weight. Formula: P=W/t = work/time, that is, P=W/t.

Answer: Measure the vertical height h of the three-story building with a meter ruler.

B: Use a watch to measure the time t for people to climb from the bottom of the building to the third floor.

C: use P=W/t=mgh/t to calculate the power of people who climb the building.