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C4 rotation help

For the Question 10(iii), Find the capacity of the vase in litres
I know the formula is the the integral of pi*(y+4) between 12 and 0.
After solving this, I get the ans of 120*pi cm^3
am I right or not?
however, I don't know how to express 120*pi cm^3 in litres, ( the ans is 3 litres). Can anyone help me to solve this pls? Thx for ur help..

Original post by alexlct054

You've integrated correctly, however you've not taken into account that each unit represents 2 cm.

however, I don't know how to express 120*pi cm^3 in litres, ( the ans is 3 litres). Can anyone help me to solve this pls? Thx for ur help..

1000 cm^3 = 1 litre. And take it from there; with your corrected value.

Reply 2

han.b

ok, i get 120*pi units ^3 not cm^3

because it says that each unit of x and y represents 2cm so we have '120*pi * 8 cm^3'

8 because 2^3 = 8

so thats 960*pi

now 1000cm^3 = 1 litre

so 960*pi / 1000 = 3.015... litres and round that up to 3 litres

:smile: