Solving this rate of decay problem -- Mass loss calculation

chwala
Gold Member
Messages
2,827
Reaction score
415
Homework Statement
Kindly see attached.
Relevant Equations
exponential function and its derivatives
My interest is on question ##11.ii## only. I think there is a mistake on the markscheme...i just need a second opinion on this...find attached the question and markscheme...
1626379781217.png


markscheme here:
1626379870057.png


it ought to be,
##e^{0.0277t}=1.6797##
 
Physics news on Phys.org
Given the precision in the previous step, quoting anything more precise 1.7 is probably pushing it.
 
Reply
  • Like
Likes PhDeezNutz and chwala
Orodruin said:
Given the precision in the previous step, quoting anything more precise 1.7 is probably pushing it.
I think mark scheme is just fine...you are also correct...i would probably say ##1.68## to 3 significant figures...
 

Thread 'Prove that the integral is equal to ##\pi^2/8##'

Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
View full post »

Thread 'Finding the nth roots of a complex number'

There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
View full post »

Similar threads

Solve the given vector problem
Replies
1
Views
1K
Find the mode, median and mean of the number of children
Replies
7
Views
3K
Solve this problem that involves induction
Replies
7
Views
2K
CIE A'level question on toppling of connected solids
Replies
7
Views
2K
Solve Optimisation Problem: 2 Attached Files & Markscheme Explained
Replies
3
Views
2K
I Mass Loss on an HR diagram
Replies
1
Views
1K
Find the surface area of the water in the given prism
Replies
3
Views
2K
An interesting GCSE question: Why are electric lamps connected in parallel in house wiring?
Replies
14
Views
451
Rate of Air Loss Through a Hole in a Spaceship
Replies
1
Views
1K
How to calculate the monthly interest rate?
Replies
12
Views
2K

Hot Threads

Recent Insights

Back
Top