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What is the volume of a sphere with a radius of 3.5 cm? (Use pi = 22/7)
179.67┬аcm3
180.50┬аcm3
175.25┬аcm3
160.00┬аcm3
179.67┬аcm3
Since r=3.5=27тАЛ, then r3=8343тАЛ. The volume becomes 34тАЛimes722тАЛimes8343тАЛ, which simplifies to 311imes49тАЛтЙИ179.67.
Radius of the sphere r = 3.5 cm, pi = 22/7
V=34тАЛimes╧Аimesr3
Since r=3.5=27тАЛ, then r3=8343тАЛ. The volume becomes 34тАЛimes722тАЛimes8343тАЛ, which simplifies to 311imes49тАЛтЙИ179.67.
Students often use the surface area formula 4╧Аr2 instead of the volume formula 34тАЛ╧Аr3.
Identify Given Values
The radius r is given as 3.5 cm, which can be written as the fraction 27тАЛ cm to simplify calculations.
r=27тАЛ┬аcm
Apply Volume Formula
Substitute r=27тАЛ and ╧А=722тАЛ into the volume formula for a sphere: V=34тАЛ╧Аr3.
V=34тАЛimes722тАЛimes(27тАЛ)3
Perform Calculation
Expand the cube: (27тАЛ)3=8343тАЛ. Now calculate V=34тАЛimes722тАЛimes8343тАЛ.
V=3imes7imes84imes22imes343тАЛ=311imes49тАЛ=3539тАЛ
Final Division
Dividing 539 by 3 gives the final volume of approximately 179.666..., which rounds to 179.67.
VтЙИ179.67┬аcm3
A is correct because the calculation of the volume using the formula results in approximately 179.67 cm┬│.
Always convert decimal radii to fractions when the constant ╧А involves 7 in the denominator to avoid rounding errors during intermediate steps.