You know that friction also causes heat. Think about when you rub your hands together. It is friction that makes them warm. But why does this happen? Friction causes the molecules on rubbing surfaces to move faster. Faster moving particles have more heat energy. Heat from friction can be useful. Can you think of other places where you might find friction? Friction also lets you light a match. Heat from friction can also cause problems. It can cause a car to overheat. To reduce friction, oil is added to the engine. Oil coats the surfaces of moving parts. This coating of oil makes them slippery. When things are slippery there is less friction. Have you ever seen a sign that says, slippery when wet? This too has to do with friction. Water, like oil, can reduce friction. The wet surface may allow your shoes to slide more easily.

What problem can friction cause?

Alexander Sergeyevich Pushkin (/'pUSkIn/; Russian: Aleksandr Sergeevich Pushkin, tr. Aleksandr Sergeyevich Pushkin; IPA: [aljI'ksandr sjI'rgjejIvjItc 'puskjIn]; 6 June [O.S. 26 May] 1799 - 10 February [O.S. 29 January] 1837) was a Russian author of the Romantic era who is considered by many to be the greatest Russian poet and the founder of modern Russian literature. Pushkin was born into Russian nobility in Moscow. His matrilineal great grandfather was Abram Gannibal, who was brought over as a slave from what is now Cameroon. Pushkin published his first poem at the age of fifteen, and was widely recognized by the literary establishment by the time of his graduation from the Tsarskoye Selo Lyceum. While under the strict surveillance of the Tsar's political police and unable to publish, Pushkin wrote his most famous play, the drama Boris Godunov. His novel in verse, Eugene Onegin, was serialized between 1825 and 1832. Notoriously touchy about his honour, Pushkin fought as many as twenty-nine duels, and was fatally wounded in such an encounter with Georges-Charles de Heeckeren d'Anthes. Pushkin had accused D'Anthes, a French officer serving with the Chevalier Guard Regiment of attempting to seduce the poet's wife, Natalya Pushkina.

Which Russian noble is consider the founder of modern Russian literature?

Hannah Harvey was a ten year old that had many friends in school. She lived in New York and enjoyed doing gymnastics and playing soccer. One day, Hannah came home from school and her parents greeted her. She knew that something was different by the expressions on their faces. Even Jackson, Hannah's dog, was acting different. Hannah asked why everyone was being so strange. Hannah's father, who was known as Pop, explained to Hannah that his job was forcing him to move. Hannah did not seem to think this was too big of a deal. Then, Hannah's mother explained that they were moving to Kenya. Kenya, she explained, was a place in Africa and life would be very different there. As Hannah began to cry thinking about all of her friends at home, Hannah's mother calmed her with a gentle touch. Jackson began howling as Hannah cried, but was also calmed by Hannah's mother. Hannah spent the next two weeks visiting her friends and saying her goodbyes. She did not know the next time she would be home. She cried very hard when she said goodbye to her best friend, Susan. Susan did not quite understand where Kenya was, but promised to visit Hannah. The next day, Hannah boarded a plane with her family. At first, they thought that Jackson could not come with them. However, Hannah worked hard and helped make sure that he had all of his shots so that he could come. After he had them all, the airport said it was OK for Jackson to come! The Harvey family left and off they went across the ocean to begin their new life in Kenya.
Why was Hannah crying about her friends at home?