A paper weight has the shape of a half-cone with a diameter of 10 cm and a vertical height of 15 cm. Using the information, calculate the following: [Take pi=3.142]
(a) total volume of the paper weight
(b) curved surface area of the paper weight
Juz like 2 double check whether my ans is correct...
(a) 196 cm3 (3 sig fig) (b) 124 cm2 (3 sig fig)
a correct
b wrong.
For (b), this is how i solve:
formula for curved surface area of half-cone = 0.5 x pi x r x l
where r= 5,
l= square root of 250 (using pythagoras' theorem to obtain value of slant height)
pls comment...
Originally posted by Dixon999:For (b), this is how i solve:
formula for curved surface area of half-cone = 0.5 x pi x r x l
where r= 5,
l= square root of 250 (using pythagoras' theorem to obtain value of slant height)
pls comment...
you need to include the base area (half of a circle) and one cross sectional area as well
the qn onli ask 2 calculate curved surface area not total suface area
Originally posted by Dixon999:the qn onli ask 2 calculate curved surface area not total suface area
oh ya, then in that case, you are right.