Ask Singapore Homework?

Upload a photo of a Singapore homework and someone will email you the solution for free.



Question

secondary 4 | E Maths
2 Answers Below

Anyone can contribute an answer, even non-tutors.

Answer This Question
tiffany
Tiffany

secondary 4 chevron_right E Maths chevron_right Singapore

hi i need help

Date Posted: 2 years ago
Views: 347

See 2 Answers

done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
Danny Low
Danny Low's answer
1017 answers (Tutor Details)
1st
Hope this helps
Boy Mow Chau
Boy Mow Chau
2 years ago
the ball should contact the wall, floor AND cylinder, so ED is not diameter of ball.

let radius of ball be r, then
(sqrt[2] x r) + r = ED
r (sqrt[2] + 1) = 2 sqrt[2] -2
r= 6-4sqrt[2]
= 0.34314

volume of ball
= (4/3) pi (0.34314)^3
= 0.16924 ...
= 0.17 m3 (to 2 d.p.)

have tried to draw a scaled diagram of a cylinder against floor and wall, and a ball squeezed into the corner. from the diagram, the radius of the ball corresponds quite closely to the calculated radius of 0.343145 above.

the exact value of r above is obtained by simplifying the surds. for students who do not do A maths, can still find r by converting the surds to the corresponding decimals.
done {{ upvoteCount }} Upvotes
clear {{ downvoteCount * -1 }} Downvotes
Danny Low
Danny Low's answer
1017 answers (Tutor Details)
Sorry I made a mistake in the last step. Here’s the correct answer. Hope this helps
Boy Mow Chau
Boy Mow Chau
2 years ago
sorry, but i believe ED in diagram above is not the correct diameter of ball.

please see comments in answer above.
Danny Low
Danny Low
2 years ago
Noted. I realised the mistake. Thanks for the correction