MYTUTOR SUBJECT ANSWERS

184 views

The number of uniform spherical shots that can be made from a given mass of lead varies inversely to the cube of the radius. When the radius is 1mm the number of shots made is 2744. How many shots of radius 1.4mm can be made from the same mass.

The key to long questions like these is picking out the key information quickly.

We have 2 pieces of information we are interested in, the number of shots and the radius of each shot, so let's assign them a letter.

let n = # of shots that can be made

let r = radius of each shot

We know, from the question, the number of shots is inverseley proportional to the radius of each shot. i.e. 

n = k/r3

We see in the equation above that n is equal to some number ( a constant ) divided by r3. If we could find this constant we would be able to substitute in our radius to find the number of shots.

To find the constant let's substitute in the information we already have

2744 = k/13

therefor k = 2744

Now it should be easy to get that n to pop out

n = 2744/1.43

Although you will most likely use a calculator for this last step, write down the calculation anyway so the examiner knows what you have done. 

n = 1000

Joshua J.

5 months ago

Answered by Joshua, a GCSE Maths tutor with MyTutor


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

454 SUBJECT SPECIALISTS

£18 /hr

Joe C.

Degree: General Engineering (Masters) - Durham University

Subjects offered: Maths, Science+ 3 more

Maths
Science
Physics
Computing
.STEP.

“Masters student at Durham University, ready to help you excel at Maths and Science ”

MyTutor guarantee

£18 /hr

Rhys M.

Degree: Economics (Bachelors) - Durham University

Subjects offered: Maths, History+ 2 more

Maths
History
Geography
Economics

“About Me I am currently studying Economics at Durham University. Economics is a very broad subject, so I am very passionate about many other subjects and do a lot of reading around my subject. I was delighted to be awarded the top spo...”

£18 /hr

Roma V.

Degree: Mathematics, Operational Research, Statistics and Economics (Bachelors) - Warwick University

Subjects offered: Maths, Further Mathematics + 1 more

Maths
Further Mathematics
Economics

“Top tutor from the renowned Russell university group, ready to help you improve your grades.”

MyTutor guarantee

About the author

£18 /hr

Joshua J.

Degree: Mathematics (Masters) - Durham University

Subjects offered: Maths, Further Mathematics + 1 more

Maths
Further Mathematics
Computing

“About Me I am a first year undergraduate student studying Mathematics at Durham University and have a great passion for this subject. I have, throughout college, tutored other students and helped them to really understand the course ...”

MyTutor guarantee

You may also like...

Other GCSE Maths questions

Solve the simultaneous equations: 3a + 2b = 17 and 4a - b = 30

The number of uniform spherical shots that can be made from a given mass of lead varies inversely to the cube of the radius. When the radius is 1mm the number of shots made is 2744. How many shots of radius 1.4mm can be made from the same mass.

How do I factorise 3xy^2 – 6xy fully?

View GCSE Maths tutors

Cookies:

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

mtw:mercury1:status:ok