Question

Calculate the maximum absolute uncertainty for R if:

R = B - A
A = 32 +/- 2 seconds
B = 11 +/- 3 seconds

43 seconds


1 second


21 seconds


5 seconds


6 seconds

Answer 1

ΔR = 5 s

Step-by-step explanation:

The absolute uncertainty or error in an expression is

ΔR = |
`(dR)/(dB)` | ΔB + |
`(dR)/(dA)` | ΔA

the absolute value guarantees to take the unfavorable case, that is, the maximum error.

We look for the derivatives

`(dR)/(dB)` = 1

`(dR)/(dA)` = -1

we substitute

ΔR = 1 ΔB + 1 ΔA

of the data

ΔB = 3 s

ΔA = 2 s

ΔR = 3 + 2

ΔR = 5 s