Mass energy equation

In physics, mass–energy equivalence is a concept formulated by Albert Einstein that explains the relationship between mass and energy. It states every mass has an energy equivalent and vice versa—expressed using the formula

E = mc²                                 

where E is the energy of a physical system, m is the mass of the system, and c is the speed of light in a vacuum  (about 3×10⁸ m/s). In words, energy equals mass multiplied by the speed of light squared. Because the speed of light is a very large number in everyday units, the formula implies that any small amount of matter contains a very large amount of energy. Some of this energy may be released as heat and light by chemical or nuclear transformations. This also serves to convert units of mass to units of energy, no matter what system of measurement units used.

Mass–energy equivalence arose originally from special relativity as a paradox described by Henri Poincaré. Einstein proposed it in 1905, in the paper Does the inertia of a body depend upon its energy-content?, one of his Annus Mirabilis ("Miraculous Year") Papers. Einstein was the first to propose that the equivalence of mass and energy is a general principle and a consequence of the symmetries.

A consequence of the mass–energy equivalence is that if a body is stationary, it still has some internal or intrinsic energy, called its rest. Rest mass and rest energy are equivalent and remain proportional to one another. When the body is in motion (relative to an observer), its total energy is greater than its rest energy. The rest mass (or rest energy) remains an important quantity in this case because it remains the same regardless of this motion, even for the extreme speeds or gravity considered in special and general relativity; thus it is also called the invariant mass.

English reported speech exercise

Q: Change the following into reported speech.

1. She asked, “Is there a shopping center near here?”
2. He says, “I am doing my duty.” 
3. She said to me, "I am a good dancer." 
4. Mohan said to me, "I clean the black shoes."
5. She said, "I went to the cinema yesterday." 
6. She said, "I am not hungry now."
7. The owner said to the servant, “Will you come tomorrow?” 
8. They said, "We were in Paris last week."
9. She said, "I don't know where my shoes are."
10. The teacher said to the students, “The sun rises in the east and sets in the west.”
11. He says, “I shall go to Delhi.” 
12. Rita said, "I cleaned my black jacket yesterday."
13. He said to me, “I have never seen such a lazy boy as you are.”
14. He said to me, “Why did you insult my brother?”
15. The teacher said to the students, “Work hard and be regular in your studies.”
16. She said to me, “What are you doing?”
17. Meena asked her, "When did you come?"
18. She said to us, “Let us play some music.”
19. “What a terrible storm it is!”, he said
20. He said “Good bye friends.”

History 8th
Important questions 

• 1. What is caste system?
• 2. Who has started the Satya Shodak Samaj?
• 3. Who are known as dalits?
• 4. Who has started the Anti-Untouchability League?
• 5. What is the occupation of vaishyas?
• 6. Why did British set up the municipal corporation?
• 7. Name one hill station established by the British in India.
• 8. What was the capital of India in 1772?
• 9. What feature of Delhi attracted countless empires to make it their capital?
• 10. Who was started the newspaper named Sambandh Kaumudi?