year 10 signpost 5.3 exercise 6:07 (1 Viewer)

[jennersfart]

So i dont understand Q4 primarily because of no diagram and Q5 is confusing

Q4. Calculate the volume of a spherical shell that has an inner radius of 5cm and an outer radius of 6cm. Give the answer in terms of pi π .

Q5 a. A sphere has a volume of 2000cm^3. Calculate its radius correct to 1 decimal place.

b. What is the smallest radius a sphere can have if it has to have a volume greater than 5000cm^3? Round your answer up to the nearest whole number.

c. A sphere has to have a volume of 1m^3. What is the radius of the sphere? Round your answer up to the nearest centimetre.

 

[Kurosaki]

So i dont understand Q4 primarily because of no diagram and Q5 is confusing

Q4. Calculate the volume of a spherical shell that has an inner radius of 5cm and an outer radius of 6cm. Give the answer in terms of pi π .

Q5 a. A sphere has a volume of 2000cm^3. Calculate its radius correct to 1 decimal place.

b. What is the smallest radius a sphere can have if it has to have a volume greater than 5000cm^3? Round your answer up to the nearest whole number.

c. A sphere has to have a volume of 1m^3. What is the radius of the sphere? Round your answer up to the nearest centimetre.

Hmm, for question 4, it's asking about a hollow sphere. So imagine a sphere that has a radius of 6 cm. Then inside this sphere, there is another sphere of empty space, and the centre of this sphere is the same as that of the outer sphere. Does that help you visualise it a bit better?

For question 5, what part exactly do you have trouble with?

 

[jennersfart]

Hmm, for question 4, it's asking about a hollow sphere. So imagine a sphere that has a radius of 6 cm. Then inside this sphere, there is another sphere of empty space, and the centre of this sphere is the same as that of the outer sphere. Does that help you visualise it a bit better?

For question 5, what part exactly do you have trouble with?

thanks I've realised where i went wrong it makes sense now i thought that the inner and outer radius where separate from each other and so it confused me but its all cleared up now Q5 is also sorted out thanks to the person below