# Physics Alevel uncertainties question help!!!Watch

#1
"the diameter of a solid sphere is measured with vernier calipers to be 4.73 ±0.01cm and its mass is measured to br 429.2±0.01g"

they ask us to find the percentage uncertainty of the density of the sphere.

ive been on this question for the past 2 hours i think i need help
0
1 month ago
#2
density = mass/volume
density = m/(4/3πr3)

4/3π has no uncertainty, so ignore that part.
You're left with m/r3 for determining uncertainty.

Start by finding the percentage uncertainty in the mass and the radius. r is cubed, so it has triple the percentage uncertainty of r. Then it's m/r3 so you add together the percentage uncertainties of m and r3.

This thread may help if you don't understand: https://www.thestudentroom.co.uk/sho....php?t=2661762
0
X

new posts
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### University open days

• Keele University
Thu, 27 Jun '19
• Birkbeck, University of London
Thu, 27 Jun '19
• University of Birmingham
Fri, 28 Jun '19

### Poll

Join the discussion

#### What was the hardest A-level paper of 2019?

Edexcel Maths paper 1 (59)
22.1%
Edexcel Maths paper 2 (91)
34.08%
AQA Chemistry Paper 2 (57)
21.35%
Edexcel Maths Paper 3 (25)
9.36%
AQA Physics Paper 3 (35)
13.11%