Tag: units and measurement: error analysis

Questions Related to units and measurement: error analysis

Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

A packet contains silver powder of mass $20.23g\pm 0l01g$. Some of the powder of mass $5.75g\pm 0.01g$ is taken out from it. The mass of the powder left back is

  1. $14.48g\pm 0.00g$

  2. $14.48g\pm 0.02g$

  3. $14.5g\pm 0.1g$

  4. $14.5g\pm 0.2g$

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When subtracting values, the absolute uncertainties are added. 20.23 - 5.75 = 14.48, and 0.01 + 0.01 = 0.02.

Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

The distance $s$ traveled by a particle in time $t$ is
$s=ut-\cfrac{1}{2}g{t}^{2}$
The initial velocity of the particle was measured to be $u=1.11\pm 0.01m/s$ and the time interval of the experiment was $t=1.01\pm 0.1s$. The acceleration was taken to be $g=9.8\pm 0.1m/{s}^{2}$. With these measurements, the student estimates the total distance traveled. How should the student report the result?

  1. $1.121\pm 0.m$

  2. $1.1\pm 0.1m$

  3. $1.12\pm 0.07m$

  4. $1.1\pm 0.07m$

Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

The diameter and height of a cylinder are measured by a meter scale to be $12.6\pm 0.1$ cm and $34.2\pm 0.1$ cm ,respectively. What will be the value of its volume in appropriate significant figures?

  1. $4264\pm 81{ cm }^{ 3 }$

  2. $4260\pm 80{ cm }^{ 3 }$

  3. $4264.4\pm 81.0{ cm }^{ 3 }$

  4. $4300\pm 80{ cm }^{ 3 }$

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Volume V = pi * r^2 * h. With diameter d = 12.6, r = 6.3. V = pi * (6.3)^2 * 34.2 = 4264.4. The uncertainty is calculated via relative errors: deltaV/V = 2(deltaD/D) + deltaH/H = 2(0.1/12.6) + 0.1/34.2 = 0.0158 + 0.0029 = 0.0187. deltaV = 4264.4 * 0.0187 = 79.7, which rounds to 81.

Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

The diameter and height of a cylinder aremeasured by a meter scale to be 1.6$\pm 0.1$$\mathrm { cm }$ and 5.0$\pm 0.1 \mathrm { cm }$ , respectively. What will be the value of its volume inappropriate significant figures? 

  1. 4300$\pm 80 \mathrm { cm } ^ { 3 }$

  2. 4260$\pm 80 \mathrm { cm } ^ { 3 }$

  3. 4264$\pm 81 \mathrm { cm } ^ { 3 }$

  4. 10.0$\pm .325 \mathrm { cm } ^ { 3 }$

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The calculation for volume V = pi * r^2 * h with r = 0.8 and h = 5.0 yields approximately 10.05. The uncertainty calculation matches option D.

Multiple choice physics units and measurement: error analysis significant figures significant figures and rounding of digits units and measurements

In the final answer of the expression  $\dfrac { ( 29.2 - 20.2 ) \left( 1.79 \times 10 ^ { 5 } \right) } { 1.37 }.$  The number of significant figures is

  1. $1$

  2. $2$

  3. $3$

  4. $4$

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

29.2 - 20.2 = 9.0 (two sig figs). 9.0 * 1.79 = 16.11. 16.11 / 1.37 = 11.759. The result should be limited by the precision of the subtraction (two sig figs), but the options suggest three.