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Find the volume of a sphere whose diameter is 84 m. [Use π=722]
323,434 m3
310,464 m3
338,808 m3
313,418 m3
310,464 m3
Find the radius r=42 m, use V=34×722×423. Note that 423 is divisible by 7×3=21, making the calculation straightforward.
Diameter of the sphere d=84 m, π=722
V=34πr3
Find the radius r=42 m, use V=34×722×423. Note that 423 is divisible by 7×3=21, making the calculation straightforward.
Using the diameter directly as the radius instead of dividing by 2.
Step 1: Find the radius of the sphere
Given the diameter d=84 m, the radius r is half of the diameter.
r=2d=284=42 m
Step 2: State the formula for the volume of a sphere
The volume V of a sphere is given by the formula in terms of radius r.
V=34πr3
Step 3: Substitute the values into the formula
Substitute π=722 and r=42 m into the volume expression.
V=34×722×(42)3
Step 4: Calculate the final volume
Compute the value: 423=74088. Dividing by 21 gives 3528, and multiplying by 4×22=88 yields 310,464 m3.
V=3×74×22×42×42×42=310,464 m3
B is correct because the calculated volume of the sphere with diameter 84 m is 310,464 m3.
Always verify if the radius is divisible by 7 when π=722 is specified to simplify fraction cancellation.