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Answer: t = 6 s
Step-by-step explanation:
When Rose hit the water, the height of the jump is 0, so: h(t) = 0.
Resolving it, we have:
-16t² + 16t + 480 = 0
To simplify the second degree equation, divided it by 16:
-t² + t + 30 = 0
Now, solve the equation using Bhaskara:
Δ = 1² - 4. (-1) . 30
Δ = 1 + 120
Δ = 121
t =
t₁ = = - 5
t₂ = = 6
Since time can be negative, it took t = 6s for Rose to hit the water.
Answer: See figure 2 in the diagram below for the table.
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Explanation:
The steps are fairly lengthy to explain in words, but the process is fairly straightforward. Start with figure 1 in the diagram below. The letters A through O represent the steps you'll take to replace them. For instance, you'll replace A with 219 since that's the grand total. Then B is replaced with 137 since we're told that 137 girls were surveyed. Then C gets replaced with 219-137 = 82, and so on. Use arithmetic (adding and subtracting) to gradually replace each letter with the proper number as figure 2 shows. The alphabetical order directly corresponds to the order in which the values are given by your teacher (eg: 219 is first, then 137 next, and so on).
Let me know if you get stuck on any one step, or need me to go into more detail.
