8. A man walks at the rate of 4 miles per hour. How far can he walk into the country and ride back on a trolley that travels at the rate of 20 miles per hour, if he must be back home 3 hours from the time he started? 9. A boy rides away from home in an automobile at the rate of 28 miles an hour and walks back at the rate of 4 miles an hour. No one wants to write or talk about numbers that have 20 digits in them! So to measure really long distances, people use a unit called a light year. Light travels at 186,000 miles per second (300,000 kilometers per second). Therefore, a light second is 186,000 miles (300,000 kilometers). A light year is the distance that light can travel in a ... As the climate warms, how much, and how quickly, will Earth's glaciers melt? So far, the results have been positively chilling. When President Taft created Glacier National Park in 1910, it Thawing permafrost has caused the ground to subside more than 15 feet (4.6 meters) in parts of Alaska. Now Louisiana is losing approximately 25 square miles (65 square kilometers) of wetlands every year, and...På ELLE.dk deler vi de bedste modenyheder, tendenser og budgetfund. Se alt om modeller, modeuger, makeup, skønhedspleje og stilfuld indretning.