the radii of the circular ends of a bucket of height 15cm are 14cm and r cm (r<14). If the volume of the bucket is 5390 cm3, then find the value of r. [use π=22/7]
Attachments:
Answers
Answered by
5
we know that,
volume of bucket=πh/3(R^2 + r^2 +R.r)
5390=π×15/3(14^2 +r^2 + 14r)
5390=5π(196 +r^2 +14r)
1078×7/22=r^2 + 14r +196
343=r^2 +14r + 196
r^2+14r -147=0
r^2 +21r- 7r -147=0
r(r+21) -7(r +21)=0
(r+21)(r-7)=0
therefore,r=7 or - 21
we know that, radius can never be in negative.
therefore -21 is neglected.
Hence, radius=7 Ans☺️☺️☺️☺️☺️☺️☺️☺️
volume of bucket=πh/3(R^2 + r^2 +R.r)
5390=π×15/3(14^2 +r^2 + 14r)
5390=5π(196 +r^2 +14r)
1078×7/22=r^2 + 14r +196
343=r^2 +14r + 196
r^2+14r -147=0
r^2 +21r- 7r -147=0
r(r+21) -7(r +21)=0
(r+21)(r-7)=0
therefore,r=7 or - 21
we know that, radius can never be in negative.
therefore -21 is neglected.
Hence, radius=7 Ans☺️☺️☺️☺️☺️☺️☺️☺️
Similar questions