MYTUTOR SUBJECT ANSWERS

528 views

Work out the ratio between the surface area of sphere of radius 6cm and the total surface area of a hemisphere of radius 9cm.

Here you need to use two formulae; one for the surface area of a sphere (4πr2) and one for the area of a circle (πr2).

First the surface area of the 6cm radius sphere:
Area=4π(62)=144π

Second the area of the 9cm radius hemisphere:
Area=4π(9)2/2+π(92)=162π+81π=243π
The surface area must be divided by 2 for the hemisphere, as it is half a sphere. The area of the circular base of the hemisphere must be added, hence the πr2 term.

This gives a ratio of 144π:243π. This can be simplified to 16:27 when both sides are divided by 9π.

Liam P. A Level Biology tutor, GCSE Biology tutor, GCSE Maths tutor

11 months ago

Answered by Liam, a GCSE Maths tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

461 SUBJECT SPECIALISTS

£18 /hr

Toluwalase F.

Degree: Mechanical Engineering (Masters) - Nottingham University

Subjects offered:Maths, Physics+ 2 more

Maths
Physics
Philosophy and Ethics

“Mechanical Engineering(MEng).Completed the IB with a 7 in Higher Physics and a 6 in Maths.Progression tracked through regular short answer tests.”

Katrina M. IB Maths tutor, 13 Plus  Maths tutor, GCSE Maths tutor, A ...
£18 /hr

Katrina M.

Degree: Mathematics Bsc (Bachelors) - Exeter University

Subjects offered:Maths, Physics+ 2 more

Maths
Physics
Further Mathematics
-Personal Statements-

“Hi, I am a patient, experienced and enthusiastic tutor ready to help each student reach their full potential.”

£24 /hr

Sioned D.

Degree: Law (Bachelors) - University College London University

Subjects offered:Maths, History+ 4 more

Maths
History
English
Biology
.LNAT.
-Personal Statements-

“Hello! I'm a University College London Final year Law Student with a great deal of tutoring experience in English, Maths, Sciences and Entrance Exams. ”

About the author

Liam P.

Currently unavailable: for regular students

Degree: Biological Sciences with integrated masters (Masters) - Durham University

Subjects offered:Maths, Biology

Maths
Biology

“A little bit about me I am currently studying for my masters in Biology at the University of Durham. In the coming year I will be working on modelling the effect of climate change on migratory birds. I found studying bird migration fa...”

MyTutor guarantee

You may also like...

Posts by Liam

Describe how different environmental factors affect the direction of root and shoot growth in plants. You should refer to the role of plant hormones.

Explain what is meant by codominant alleles.

Solve the quadratic equation: 5x2+8x+2

Work out the ratio between the surface area of sphere of radius 6cm and the total surface area of a hemisphere of radius 9cm.

Other GCSE Maths questions

Find the equation of the line passing through the point ( 2, −3) which is parallel to the line with equation y + 4x = 7

Solve: 3(x - 2) = 21

N=2a+b, where a is a two-digit square number and b is a two-digit cube number. What is the smallest possible value of N?

Bag A contains £7.20 in 20p coins. Bag B contains only 5p coins. The number of coins in bag B is three-quarters of the number of coins in bag A. How much money is in bag B?

View GCSE Maths tutors

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok