😅😅😅😅 0:38 0:42

Everything is fine but one big mistake in this video is repeatedly confusing reflection for scattering. All that sir explained was scattering/deflection and not reflection, example for reflection is skys reflection on a lakes surface. And blue colour of ocean is MOSTLY due to scattering and not reflection.

11: 38pm

Avul pakir jainulabdeen Abdul Kalam

4:01 mass to object ka hona chaiye na

radium causes cancer... There is no radium in the watch

Teacher ❌ Hero ✔️

Mai bhi ye hi soch rahi thi physics ka topic hoga bcz tution lekar bhi pass hi ho pate the baal baal bache lekin baad me bsc me physical chemistry dushman bani Commerce and economics is also quite complicated subject.

2:02 she said😂😂

2:01

Please speak in Hindi

❤ good explanation 👏 👌

If watches contain radium which is radioactive, won’t it generate continuous radiations? Which could even harm us?

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Aapna bohot hi acha samjya h🎉🎉

Electric current 5:06

radium is too expensive and dangerous for labours to handle they use something else they used to paint hands with radium in old time not now youtubers nowa days shit without research

Samaj ma nahi a ra ha

Njdbyvv❤❤🎉😢😮😅😊

Hopeless scientific communities, all bunch of idiots together 🙄. This is not a solution but, a rapid advancement towards disaster! ☝️ Poor humans 😔

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❤❤❤❤❤

Why the sun will not move 🤔🤔

Maine spaceahip dekha tha such me location Maharashtra

Area is Vector quantity

Johnson Karen Lee Kenneth Harris Daniel

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Smith George Jones Carol Hernandez David

Jackson Deborah Gonzalez Helen Martinez Karen

Mat samajh phir

Rifoidodli

Clark Susan Young Melissa Wilson Charles

But can't make artificial sperm

Easy ❌ hard✅

Sir g that is motion

Radium, a highly radioactive element, was commonly used in the early 20th century to create luminescent dials on watches, clocks, and other instruments. This practice was especially popular from the 1910s to the 1960s. The glow was made possible by mixing radium with phosphorescent materials, producing a bright and long-lasting light without requiring an external power source. However, the use of radium in watches had serious, often tragic consequences, both for the workers who painted the dials and for the broader public. ### The Appeal of Radium Radium was discovered by Marie and Pierre Curie in 1898. Its unique properties, especially its ability to emit a continuous glow, quickly captured the public's imagination. By the 1910s, radium became a symbol of modernity and innovation. Radium-based paint, often called "Undark," was used in various consumer products, most notably in wristwatches. These glowing watches were especially popular among soldiers during World War I, as they allowed time to be read in the dark. ### The "Radium Girls" The workers, primarily women, who painted these dials were known as the "Radium Girls." They were often instructed to "lip, dip, and paint" - a technique where they used their lips to bring the brush to a fine point before dipping it into the radium paint. Unaware of the dangers, the women ingested small amounts of radium every time they did this. Radium, being chemically similar to calcium, accumulated in their bones, leading to severe health problems. ### Health Consequences The effects of radium exposure were devastating. Many Radium Girls suffered from anemia, bone fractures, and necrosis of the jaw, a condition later termed "radium jaw." The symptoms were initially mysterious and terrifying, as radium poisoning was not well understood. The long-term exposure led to severe radiation poisoning, and many workers died in their 20s and 30s from cancers or other radiation-related illnesses. ### Public Awareness and Legal Battles As the health crisis among the Radium Girls became impossible to ignore, it led to one of the first occupational disease lawsuits in the United States. In the late 1920s, some affected women sued the United States Radium Corporation. The case brought significant public attention to the dangers of radium, and the women eventually won, although many of them had already died or were gravely ill. Their fight played a crucial role in the development of labor rights and industrial safety standards, highlighting the need for regulations to protect workers from hazardous materials. ### The Decline of Radium in Consumer Products The radium dial industry continued for some time after the Radium Girls scandal, but with growing public awareness and scientific understanding of the dangers of radioactivity, safer alternatives were sought. By the 1960s, radium was largely replaced by safer luminescent materials, such as tritium, which is radioactive but emits far less dangerous radiation, and non-radioactive phosphorescent paints. Today, the legacy of radium in watches serves as a stark reminder of the dangers of unchecked industrial practices and the importance of occupational health and safety. ### Modern-Day Concerns While radium is no longer used in consumer products, old radium-dial watches and instruments are still around, often collected as antiques. These items can still pose a radiation hazard if not handled properly. Though the radiation emitted by a single watch is low, the cumulative exposure from multiple items or improper disposal can be risky. Modern collectors and restorers are advised to use protective measures when handling these items to avoid unnecessary exposure. ### Conclusion The story of radium in watches is a cautionary tale of how technological innovation, when not properly understood or regulated, can lead to widespread harm. The legacy of the Radium Girls continues to resonate today, reminding us of the critical importance of worker safety, informed consent, and the need for rigorous safety standards when dealing with potentially dangerous materials.

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Fingerprint scanner par bahut hi achha explain kiye ho bhai Lekin ultrasonic sensor ke case me Sound reflect hoga na ki Light (time -11:58). Tempered glass ke thickness Jayda hone se sound ki speed affected hogi lekin light ka speed affected nahin hogi because light is an electromagnetic wave.

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"Force does not exist physically in the same way that an object with mass does. This means that force cannot make surface contact with an object, much less push or pull it. The initial cause of all bodies in motion originates from the applied energy (E), which creates the momentum (p) necessary to make surface contact with an object, thereby enabling it to push and pull. This concept is mathematically expressed as Ep or the equation Ep = ma. Force was originally used as a placeholder by Sir Isaac Newton because he did not know the true nature of this Force." ~Professor Guadalupe Guerra from Laredo, Texas c/s

Mera doubt clear ho gya

We want spectrum back...!!❤❤😢😢 Where are you dear Abhishek sir..??😢😢

Thanks sir

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Clicked the concept❤

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