Question

A body travels uniformly a distance of $(13.8\pm 0.2)m$ in a time $(4.0\pm 0.3)s$. Find the percentage error in the velocity of the body.

• A. $8.94\%$
• B. $9.85\%$
• C. $7\%$
• D. $5.95\%$

Answer 1

The correct option is A $8.94\%$

Find mean value of velocity.
$v=\frac{\text{distance}}{\text{time}}=\frac{13.8}{4.0}=3.45m/s$

Find mean absolute error in velocity.
$\frac{△v}{v}=\frac{△d}{d}+\frac{△t}{t}=\frac{0.2}{13.8}+\frac{0.3}{4.0}=0.0894△v=0.089\times 3.45=0.30m/s$
$\therefore$ Velocity=$(3.45\pm 0.3)m/s$

Find percentage error in velocity.
Percentage error,
$\frac{△v}{v}\times 100=0.0894\times 100=8.94\%$