Cups A and B are cone shaped and have heights of 32 cm and 27 cm and openings with radii of 12 cm and 13 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 22, 2018

31.9 cm high of cup A will be filled.

Explanation:

Height and radius of cup A is h_a=32 cm , r_a=12 cm

Volume om cone is 1/3*pi*r^2*h :.V_a=1/3*pi*12^2*32 or

V_a= 4825.49 cubic cm.

Height and radius of cup B is h_b=27 cm , r_b=13 cm

:.V_b=1/3*pi*13^2*27 or V_b= 4778.36 cubic cm.

Since V_a > V_b , the content will not overflow.

The ratio of radius and hight of cup A is

r/h=12/32 =3/8 . The ratio of radius and hight of water cone

is r_w/h_w=3/8 or r_w=(3*h_w)/8

. The volume of water cone is V_w=4778.36 cubic cm.

:.1/3*pi*r_w^2*h_w =4778.36 or

1/3*pi*((3*h_w)/8)^2*h_w =4778.36 or

h_w^3= (4778.36*64)/(3*pi)~~32447.9835 or

h_w= root(3)32447.9835 ~~ 31.90(2dp) cm

31.9 cm high of cup A will be filled [Ans]