contestada

1. The diagram represents a cone.
The height of the cone is 12 cm.
The diameter of the base of the cone is 10 cm.
Calculate the curved surface area of the cone.

2. A sphere has a volume of 500 m​3​.
(b) Calculate the radius of the sphere. Give your answer correct to 3
significant figures.

Respuesta :

Answer:

1. The curved surface area of the cone is 282.74 cm²

2. Radius of sphere r = 4.924 m

Step-by-step explanation:

1. Height of cone = 12 cm

Diameter of base of cone = 10 cm

Surface Area of cone = ?

The formula used is: [tex]A=\pi r(r+\sqrt{h^2+r^2})\\[/tex]

h= 12 cm

r = diameter/2 r = 10/2 = 5 cm

Putting values and finding surface area

[tex]A=\pi r(r+\sqrt{h^2+r^2})\\A=3.14*5 (5+\sqrt{(12)^2+(5)^2})\\A=15.7 (5+\sqrt{144+25})\\A=15.7 (5+\sqrt{169})\\A=15.7 (5+13)\\A=15.7(18)\\A=282.74 \ cm^2[/tex]

So, the curved surface area of the cone is 282.74 cm²

2. Sphere of Volume = 500 m³

We need to find radius of sphere

The formula used is: [tex]Volume=\frac{4}{3}\pi r^3[/tex]

Putting values and finding radius of sphere

[tex]Volume=\frac{4}{3}\pi r^3\\500=\frac{4}{3}*3.14* r^3\\500=4.186*r^3\\=> r^3=\frac{500}{4.186}\\r^3=119.446\\Taking \ cube \ root \ on \ both \ sides.\\\sqrt[3]{r^3}=\sqrt[3]{119.446}\\r= 4.924 \ m\\[/tex]

So, Radius of sphere r = 4.924 m