The volume of a sphere is 38,808 cm3. Then find the lateral surface area of a hemisphere if the radius of a sphere is twice of a hemisphere.
1. 693 cm2
2. 1296 cm2
3. 1456 cm2
4. 496 cm2
1. 693 cm2
2. 1296 cm2
3. 1456 cm2
4. 496 cm2
Correct Answer – Option 1 : 693 cm2
Given:
Volume of a sphere is 38,808 cm3
Radius of a sphere is twice of the hemisphere.
Formula Used:
Volume of a sphere = 4/3πr3
Lateral surface area of a hemisphere = 2πr2
Calculation:
Volume of a sphere = 4/3πr3
⇒ 4/3π r3 = 38,808
⇒ r3 = (38,808 × 3)/ 4π
⇒ r3 = 9261
⇒ r = 21
As radius of a sphere is twice of a hemisphere.
⇒ radius(circle) = 2 radius(hemisphere)
⇒ 21 = 2 radius(hemisphere)
⇒ radius(hemisphere) = 21/2
Now, Lateral surface area of a hemisphere = 2πr2
⇒ Lateral surface area of a hemisphere = 2π × (21/2)2
⇒ Lateral surface area of a hemisphere = 693
∴ The lateral surface area of a hemisphere is 693 cm2.