Tutor profile: Brittany W.
A ladder is leaned against a wall. The ladder is 10ft tall and the distance between the ladder and the wall at the bottom is 5ft. At what height is the ladder on the wall?
The formula to use here is a^2 + b^2 = c^2 In this formula, "c" represents the hypotenuse of the triangle and "a" and "b" represent the other two sides. We have been given the hypotenuse (c), which is the length of the ladder (10ft). We have also been given the length of one of the sides (5ft). We'll call the 5ft side "a". So let's plug in our givens: (5^2) + b^2 = (10^2) 25 + b^2 = 100 -25 -25 b^2 = 175 Then we take the square root of each side: sqrt(b^2) = sqrt(175) b = 13.2ft This means that the tip of the ladder touches the wall at 13.2ft.
Subject: Environmental Science
They say glaciers in the Arctic are melting at an increasingly rapid rate. In fact, they are melting faster than the average rise in global temperature. Why is this so?
It all comes down to the albedo effect. Have you ever noticed that the sidewalk is always cooler on your bare feet than asphalt, even though they've been under the sun for the same period of time? That is because sidewalks are lighter in color and so, reflect more of the sun's rays. Asphalt is darker in color, and therefore absorbs more heat from the sun. We say that the sidewalk has a higher albedo than asphalt since it reflects more of the sun's rays. When you consider ice in the arctic, the ice is white in color, which allows it to reflect light and keep the surrounding area cool. The more ice that is present in an area, the more heat is reflected, and the colder the surrounding area becomes. Unfortunately, when global air and ocean temperatures began to rise, coastal ice in the Arctic began to melt. As the coastal ice melted, the area it once covered was replaced by ocean water. Ocean water is much darker in color than ice and absorbs more heat from the sun, which makes the area surrounding area warmer. As the area of ice in the Arctic decreases, and the area of ocean water increases, more of the sun's rays are absorbed by the earth. This results in the increased rate of melting ice. What we end up seeing is a positive feedback loop where the melting of ice results in the melting of even more ice.
What is a symbiotic relationship?
A symbiotic relationship is a close relationship between individuals of different species. There are three basic symbiotic relationships: 1. Mutualism: In a mutual relationship, both individuals are benefitted. An example of this would be the relationship between a clown fish and an anemone. The clown fish is provided a home within the anemone, and the anemone is provided with a protector who will chase away predators. 2. Commensalism: In Commensal relationship, one individual is benefitted while the other individual is unaffected. An example of this relationship would be that between remora and sharks. Remora latch on to sharks and receive safe and easy rides around the ocean to various feeding grounds. The remora doesn't hurt the shark, but the shark does not benefit from the remoras presence either. 3. Parasitism: In a parasitic relationship, one individual benefits and the other individual is negatively impacted. An easy example of a parasite would be a flea on a dog. The flea gets to feed and breed on the dog, however, the dog is negatively impacted with bites, itchiness, and potential diseases.
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