I don't understand why that is correct.

[rejz55]

[SOLVED] Please check

Homework Statement

Find the volume of a right circular cylinder with a measured length of 2.3±0.1 and radius 0.12±0.05m.

Homework Equations

Propagation of uncertainty Multiplication: (a±uncertaitya) (b±uncertaintyb)= ab± ab[(uncertaintya/a) + (uncertaintyb / b)

Power: (a±Uncertaintya)^n = a^n ± na^n-1 (uncertaintya)

The Attempt at a Solution

radius^2= 0.12^2 ± 2*(.12^1)*0.05
= 0.0144±0.012

=(0.0144)(2.3)(Pi) ± (0.0144) (2.3) (pi) [(0.1/2.3)+(0.0144/0.012)
= .104049 ± .129383

My friend told me her answer is .10430±0.09123..she said she distributed the pi to the uncertainty..

 

[kamerling]

The Attempt at a Solution

radius^2= 0.12^2 ± 2*(.12^1)*0.05
= 0.0144±0.012

=(0.0144)(2.3)(Pi) ± (0.0144) (2.3) (pi) [(0.1/2.3)+(0.0144/0.012)

you exchanged 0.0144 and 0.012 here.

 

[rejz55]

y not? its the new value of the radius cause the radius should be squared..thanks..

 

[rejz55]

I got it right now..Thanks