Question

Adding and Subtracting with Rational NumbersThe elevation we call sea level is actually the average level of the sea. This means that at average sea level, the elevation is zero. In reality, the level of the sea rises and falls in what are called tides. Low tide is the point of lowest sea level in a tidal period. High tide is the point of highest sea level in a tidal period. The height above or below average sea level is called elevation. An elevation below sea level is considered a negative value, while an elevation above sea level is positive.Winston lives near the ocean. He regularly brings an altimeter to the beach to measure the elevation of the ocean’s surface. You will use the data Winston gathered to complete tasks about the rising and falling of the ocean’s surface. When necessary, sketch a diagram of the situation on a separate sheet of paper to assist you.On Monday at 1 p.m., when the ocean’s surface was at an elevation of 2.2 feet, Winston went to a surf shop that was 8.2 feet above the ocean’s surface. At 7 p.m. when the ocean’s surface was at an elevation of -2.4 feet, Winston ate dinner at a restaurant whose deck was 10 feet above the ocean’s surface.Part AWhat was the net change in the elevation of the ocean’s surface from 1 p.m. to 7 p.m.?Characters used: 7 / 15000Part BHow many feet apart are the two ocean elevations described in part A?Characters used: 0 / 15000Part CWhat is the elevation of the deck where Winston ate dinner?Characters used: 0 / 15000Part DWhat is the elevation of the surf shop?Characters used: 0 / 15000Part EWhat was the distance between the deck and the ocean’s surface at 1 p.m.? Which was higher, the deck or the ocean?Characters used: 64 / 15000Part FWhat was the distance between the surf shop and the ocean’s surface at 7 p.m.? Which was higher, the surf shop or the ocean?

Answer 1

The net change in ocean's elevation from 1 p.m. to 7 p.m. was -4.6 feet, and the absolute distance between the two elevations was 4.6 feet. The deck's elevation at dinner was 7.6 feet, and the surf shop's elevation was 10.4 feet. The distance between the deck and the ocean at 1 p.m. was 7.8 feet, with the deck being higher, while at 7 p.m., the surf shop was 10.6 feet above the ocean, also being higher.

Step-by-step explanation:

Part A: The net change in the elevation of the ocean's surface from 1 p.m. to 7 p.m. is found by subtracting the elevation at 1 p.m. from the elevation at 7 p.m. That is (-2.4) - (2.2) = -4.6 feet.

Part B: The number of feet apart the two ocean elevations are can be determined by finding the absolute value of the net change, which is | -4.6 | = 4.6 feet.

Part C: The elevation of the deck where Winston ate dinner is found by adding the elevation of the ocean's surface at 7 p.m. to the height of the deck. That is, -2.4 + 10 = 7.6 feet.

Part D: The elevation of the surf shop is found by adding the ocean's surface elevation at 1 p.m. to the height of the surf shop. That is, 2.2 + 8.2 = 10.4 feet.

Part E: The distance between the deck and the ocean's surface at 1 p.m. can be determined by subtracting the ocean's elevation at 1 p.m. from the height of the deck. The calculation is 10 - 2.2 = 7.8 feet. The deck was higher than the ocean at 1 p.m

Part F: The distance between the surf shop and the ocean's surface at 7 p.m. can be found by subtracting the ocean's elevation at 7 p.m. from the height of the surf shop. The calculation is 8.2 - (-2.4) = 10.6 feet. The surf shop was higher than the ocean at 7 p.m.