Rough surfaces create more friction than smooth surfaces. Thats why cars have tires. Its also why we use rubber mats in areas that might get wet. In your bathtub, you may even use No-Slip tape. No-slip is another way of saying the items has a lot of friction. In Figure 1.9, the blades of the skates are very smooth. Thats why you cant slide across ice with shoes. The soles of your shoes are much rougher than skates. The rougher surface of shoes causes more friction and slows you down. Heavier objects also have more friction. A heavy object presses down with more force. The surfaces are held together more tightly. This makes the surfaces harder to slide past each other. Did you ever try to push something heavy across the floor? Heavy objects are much harder to push than light objects.

Question: "Why do cars have tires?"

Answer: "To make them slippery"

Response: no

French and British Ties and Occupation: The daughter of Ferdinand and Isabella married the son and heir of the Holy Roman Emperor, Maximilian of Hapsburg. The Spanish crown duly passed to the Hapsburgs, and Spain remained in their hands until the feeble-minded Carlos II died in 1700, leaving no heir. France seized the chance to install the young grandson of Louis XIV on the Spanish throne. A rival Hapsburg claimant was supported by Austria and Britain, who saw a powerful Spanish-French alliance as a major threat. In the subsequent War of the Spanish Succession (17021713) most of the old kingdom of Aragon, including the Balearics, backed the Hapsburgs. Britain seized Gibraltarin the name of the Hapsburg claimantand retained it when the war was over. In 1708 Britain captured Menorca, and the magnificent harbor of Mahon (Mao), for the Royal Navy. England clung to it even when Bourbon forces captured Mallorca at the end of the war. Menorca changed hands between Britain, France, and Spain five more times in less than a century. Britain finally ceded the island to Spain in the year 1802, under the terms of the Treaty of Amiens. By 1805, Spain was once more aligned with France, and Spanish ships fought alongside the French against Nelson at Trafalgar. Napoleon came to distrust his Spanish ally and forcibly replaced the king of Spain with his own brother, Joseph Bonaparte. A French army marched in to subdue the country. The Spanish resisted and, aided by British troops commanded by the Duke of Wellington, drove the French out. What British historians call the Peninsular War (18081814) is known in Spain as the War of Independence. In the 19th century, practically all of Spain's possessions in the Americas broke away in the wake of the Napoleonic Wars, and the few that remained were lost at the end of the 19th century. The Balearics, further neglected, were beset with poverty and outbreaks of disease. However, toward the 20th century, things began to improve on the islands, with Mallorca reaping the rewards of successful agricultural crops and Menorca launching an export shoe industry.

Question: "In what century was the Balearics beset with poverty and outbreaks of disease?"

Answer: "19th"

Response: yes

Sound waves are mechanical waves. They can travel only through matter. They cannot travel through empty space. This was demonstrated in the 1600s by a scientist named Robert Boyle. Boyle placed a ticking clock in a sealed glass jar. The clock could be heard ticking through the air and glass of the jar. Then Boyle pumped the air out of the jar. The clock was still running, but the ticking could not be heard. Thats because the sound couldnt travel without air particles to transfer the sound energy. Is there any other place where sound cannot be heard? Here is a hint: is there any other place that does not have air molecules? Thats right, in space sound cannot be transferred. So can astronauts hear each other? Yes, they can, because they are in enclosed space stations or pressurized suits.In both cases, they are surrounded by air molecules. If they left their space ship and did not use their electronics, they would not be able to hear each other. Next time you watch a science fiction movie, think about this factoid. When spaceships are destroyed by hostile alien beings, there would be no sound heard. Sound waves can travel through many kinds of matter.

Question: "Why can't you hear in the vacuum?"

Answer: "Mechanical waves can only travel through matter."

Response: yes

Above were just a few things that caused habitat loss or change. There are many ways in which living organisms can affect their ecosystem. In some areas, it is because of fire management. Fire is a natural event, so managing fire correctly is very important. In other areas, fisherman have taken too many fish from one area. This places the species at risk of extinction. It also affects other living things that may rely on these fish for food. The image below shows a picture of a mine. Mining changes the Earths surface. This area may once have been a forest or a prairie. Think about how many plants and animals may once have lived here. Now it is a giant hole in the ground. Pollution is also a major factor in habitat loss and change.

Question: "How does over fishing effect an ecosystem?"

Answer: "It causes over-breeding of fishes in that area"

Response:
no