1.V=(-3/4)A+(1/2)A^2
Amy has bought an antique vase of volume 11 cm^3 from the department store.
(i) find the base area of Amy's antique vase. ans:16cm^2
(ii) A wooden box which has a shape similar to Amy's antique vase is provided to hold the vase . It is possible that the wooden box has a volume of 391.5cm^3 and a base area 36cm^2? Explain your answer. Ans:yes
F.5 math help!!!
2013-12-09 8:30 pm
回答 (1)
2013-12-10 5:41 am
✔ 最佳答案
Volume is really 11 cm^3 ? Or 116 cm^3?2013-12-09 21:41:42 補充：
I believe volume should be 116, not 11.
(i) V = 116, sub. into the expression,
116 = (-3/4)A + (1/2)A^2
464 = - 3A + 2A^2
2A^2 - 3A - 464 = 0
(A - 16)(2A + 29) = 0
A = - 29/2 (rej.) or 16 cm^2.
(ii)
Using formula of similar figure,
A1/A2 = (L1/L2)^2
36/16 = (L1/L2)^2
L1/L2 = 6/4 = 1.5.
Therefore, V1/V2 = (L1/L2)^3 = 1.5^3 = 3.375
So V1 = 3.375 x 116 = 391.5 cm^3.
So answer is yes.
收錄日期: 2021-04-25 22:40:29
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