Cups A and B are cone shaped and have heights of 34 cm and 23 cm and openings with radii of 15 cm and 17 cm, respectively. If cup B is full and its contents are poured into cup A, will cup A overflow? If not how high will cup A be filled?

1 Answer
Jan 14, 2018

32.44 cm high in cup "A" will be filled.

Explanation:

Cup B (Conical): radius and height are r_b=17 cm ; h_b =23 cm

Capcaity of Cup B is V_b=1/3*pi*r_b^2*h_b

V_b=1/3*pi*17^2*23 =6960.72 cubic cm

Cup A (Conical): radius and height are r_a=15 cm ; h_a =34 cm

Capcaity of Cup A is V_a=1/3*pi*r_a^2*h_a

V_a=1/3*pi*15^2*34 =8011.06 cubic cm

r_a/h_a=15/34 . Since the capacity of cup B is less than that of

cup A , the content will not overflow. Let the height and radius in

the content cone in cup A be h_2 and r_2

r_2/h_2=15/34 ; r_2= 15/34*h_2 ; V_c=6960.72 ; V_c is the

volume of contents in cup A :. 1/3*pi*r_2^2*h_2 =6960.72

r_2^2*h_2 =(6960.72*3)/pi or

(15/34*h_2)^2*h_2=(6960.72*3)/pi or

h^3=(6960.72*3)/pi*34^2/15^2=34150.8

:. h=root(3) 34150.8 ~~32.44(2dp) cm .

32.44 cm high in cup "A" will be filled. [Ans]