Answer:
314 m²
Step-by-step explanation:
the formula for the surface area of a sphere (As) is
As = 4×pi×r²
the radius r (half of the diameter) is clearly indicated as 5m.
so, As = 4×3.14×5² = 4×3.14×25
I don't even need a calculator for this, as 4×25 = 100
so, As = 100×3.14 = 314
(you know, when multiplying by 10, the decimal point moves right one position. multiply by 100 it moves 2 positions, and so on).
The answer to c. Is 8t+12g
The first statement is true.
The second statement is false.
The third statement is true.
Part A.
The trip starts at 8am which corresponds to 0 hrs, point (0hr, 0mi)
2hrs later it's 10am. .point (2hr, 140mi)
The average speed is the slope between 0 and 2 hrs. Remember the slope formula m = Δy/Δx
m = (140 - 0) / (2 - 0)
m = 70 mph
Part B. Average speed from 11am - 2pm
11am is point (3hr, 140mi)
2pm is point (6hr, 300mi)
As you can see from the graph, the speed or slope changes at 1pm (5,260). You Can just use the start and end points.
m = (300-140) / (6-3)
m = 160/3
53.3 mph
* It comes out the same solution as if you average the two different slopes. 2hrs at 60mph + 1 hr at 40mph = (120 + 40)/3 = 160/3
Part C. Total average speed = total distance / total time driving
He went 70 mph for 2 hrs
stopped for an hour (slope is zero, no speed)
60 mph for 2hrs
40mph for 1 hr
300mi /5hr = 60mph
Part D. No Question....
We can distribute the negative to get 8 + 6i + 2 - 7i, and we can simplify that to get 10 - i.
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Hope this helps!
