contestada

what is the surface area of a sphere with a circumference of 50ft?
A. 63.3ft^2
B. 198.9ft^2
C. 398.0ft^2
D. 795.8 ft^2

the volume of a sphere if 2,254pi m^3. what is the surface area of the sphere to the nearest 10th?

A. 831.4 m^2
B. 891.6 m^2
C. 1,22.0 m^2
D. 1,1783.3 m^2

what is the scale factor of a cube with a volume 729 m^3 to a cube with volume of 6,859 m^3 ?

A. 19:9
B. 9:19
C. 361:81
D. 81: 361

Respuesta :

sphere
c=2pir
v=(4/3)pir^3
SA=4pir^2

so

first one
c=50
50=2pir
25=pir
25/pi=r
SA=4pir^2
SA=4pi(25/pi)^2
SA=4pi625/(pi^2)
SA=2500/pi
SA=795.8
D




2nd euqtion
V=2254pi
(4/3)pir^3=2254pi
divide both sides by pi
(4/3)r^3=2254
ties both sides by 3/4
r^3=1690.5
cube root both sides
r=11.9126
SA=4pir^2
SA=4pi11.9126^2
SA=4pi141.909
SA=567.636pi
SA=1783.3
D is answer


3rd
find side legnth
cube root each since V=side^3
volume 729 to 6859 is side legnths
9 to 19
every 9 units turns to 19

answer is A




D
D
A

Volume is a three-dimensional scalar quantity. The correct options are D, D, and B.

What is volume?

A volume is a scalar number that expresses the amount of three-dimensional space enclosed by a closed surface.

A.)

Circumference = 50 ft

2πR = 50 ft

R = 7.9577ft

Surface area of the sphere = 4πR² = 4×π×(7.9577ft)² = 795.8 ft²

Hence, the correct option is D.

B.)

The volume of the sphere = 2254π m³

(4/3)πR³ = 2254π m³

R = 11.9125 m

Surface area of sphere = 4πr² = 1783.3 m²

Hence, the correct option is D.

C.)

The scale factor of a cube with a volume of 729 m³ to a cube with a volume of 6,859 m³ is,

Ratio

= Side of the cube with a volume of 729m³/Side of the cube with a volume of 6,859m³

= (∛729)/(∛6,859)

= 9:19

Hence, the correct option is B.

Learn more about Volume:

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