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

` v = (S)/( t) = ( 13.8)/( 4) ; ~ 9 %`

Explanation

`v = (S)/(t) = (13.8)/(4) = 3.45 m s^(-1) ~ 3.4`
( two significant figures)
`Delta v = [( 0.2)/(13.8) + (0.3)/(4)] 3.45 = 0.3087 ~ 0.31`
( two significant figures)
` v = ( 3.4 +- 0.31) ms^(-1)`
Percentage error ` = (0.31)/(3.4) xx 100 = 9.11% ~ 9%`