Question

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

• A. $(3.45\pm 0.4)m{s}^{-1}$
• B. $(3.45\pm 0.5)m{s}^{-1}$
• C. $(3.45\pm 0.3)m{s}^{-1}$
• D. $(3.45\pm 0.2)m{s}^{-1}$

Answer 1

The correct option is C $(3.45\pm 0.3)m{s}^{-1}$

Find mean value of velocity.

$v=\frac{distance}{time}=\frac{13.8}{4.0}=3.45m/s$

Find mean absolute error in velocity.

$\frac{△v}{v}=\frac{△d}{d}+\frac{△t}{t}=0.089=△v=0.089\times 3.45=0.30m/s$

Express error in velocity.

$\therefore$Velocity=$(3.45\pm 0.3)m/s$