Question

A body travels uniformly a distance of `( 13.8 +- 0.2) m` in a time `(4.0 +- 0.3) s`. Find the velocity of the body within error limits and the percentage error.

Answer 1

Given distance `s=(13.8+-0.2)m` and time `t=(4.0+-0.3)s`
velocity `v=(s)/(t)=(13.8)/(4.0)=3.45 ms^(-1)=3.5ms^(-1)`
`(Deltav)/(v)=+-((Deltas)/(s+(Deltat)/(t)))=+-((0.2)/(13.8)+(0.3)/(4.0))=+-((0.8+4.14)/(13.8xx4.0))=+-(4.49)/(13.8xx4.0)=+-0.0895`
or `Deltav=+-0.0895xx v=+-0.0895xx3.45=+-0.3087=+-0.31`
`therefore v=(3.5+-0.31)ms^(-1)`
percentage error in velocity `=(Deltav)/(v)xx100=+-0.0895xx100=+-8.95%=+-9%`