Please only answer the exercise question at the bottom EXAMPLE 5.5Platform DiverGOAL Use conservation of energy to calculate the speed of a bodyfalling straight down in the presence of gravity.10.0 mKE; = 0PE,- mgy;PROBLEM A diver of mass m drops from a board 10.0 m above thewater's surface, as in the figure. Neglect air resistance. (a) Useconservation of mechanical energy to find his speed 5.00 m above thewater's surface (b) Find his speed as he hits the water.5.00 m-STRATEGY Refer to the problem-solving strategy. Step 1: Thesystem consists of the diver and Earth. As the diver falls, only theforce of gravity acts on him (neglecting air drag), so the mechanicalKE, = mu,?energy of the system is conserved, and we can use conservation ofenergy for both parts (a) and (b). Step 2: Choose y = 0 for thePE, =0water's surface. Step 3: In part (a), y = 10.0 m and y = 5.00 m arethe points of interest, while in part (b), y = 10.0 m and y = 0 m are of interest.SOLUTION(A) Find the diver's speed halfway down, at y = 5.00 m.Step 4: We write the energyKE, + PE, = KE, + PE,conservation equation and supply the+ mv? + mgy;+ mgy =proper terms.Step 5: Substitute v; = 0, cancel the0 + gy, -v? + gy,mass m, and solve for v,.v, = V 2g(y, - v) = V 2(9.80 m/s?)(10.0 m - 5.00 m)V = 9.90 m/s(B) Find the diver's speed at the water's surface, y = 0.Use the same procedure as in part (a),taking y- 0.0 + mgy, =mv? + 0Vr -V 2gy, - / 2(9.80 m/s²)(10.0 m) = 14.0 m/sLEARN MOREREMARKS Notice that the speed halfway down is not half the final speed. Another interesting point isthat the final answer doesn't depend on the mass. That is really a consequence of neglecting the changein kinetic energy of Earth, which is valid when the mass of the object, the diver in this case, is muchsmaller than the mass of Earth. In reality, Earth also falls towards the diver, reducing the final speed, butthe reduction is so minuscule it could never be measured.QUESTION Qualitatively, how will the answers change if the diver takes a running dive off the end ofthe board?O Answer (a) would increase and answer (b) would decrease.O Answer (b) would increase and answer (a) would decrease.Both answers would decrease.O Both answers would increase.O Both answers would remain the same.PRACTICE ITUse the worked example above to help you solve this problem. A diver of mass m drops from a board 8.00m above the water's surface, as shown in the figure. Neglect air resistance.(a) Use conservation of mechanical energy to find his speed 4.00 m above the water's surface.8.854m/s(b) Find his speed as he hits the water.v m/s12.522EXERCISEHINTS: GETTING STARTED I "M STUCK!Use the values from PRACTICE IT to help you work this exercise. Suppose the diver vaults off thespringboard, leaving it with an initial speed of 3.04 m/s upward. Use energy conservation to find his speedwhen he strikes the water.m/s

Name: Please only answer the exercise question at the bottom EXAMPLE 5.5Plat
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Description: Please only answer the exercise question at the bottom EXAMPLE 5.5Platform DiverGOAL Use conservation of energy to calculate the speed of a bodyfalling straight down in the presence of gravity.10.0 mKE; = 0PE,- mgy;PROBLEM A diver of mass m drops fro