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.

Options

A. `(3.45 +- 0.2) ms^(-1)`
B. `(3.45 +- 0.3) ms^(-1)`
C. `(3.45 +- 0.4) ms^(-1)`
D. `(3.45 +- 0.5) ms^(-1)`

Answer

b

Explanation

Here, `S= (13.8 +- 0.2)m` and `t = (4.0 +- 0.3)sec`
Expressing it in percentage error we have
`S = 13.8 +- (0.2)/(13.8) xx 100% = 13.8 +- 1.4%`
and `t = 4.0 +- (0.3)/(4) xx 100% = 4 +- 7.5 %`
`:' v = (S)/(t) = (13.8 +- 1.4%)/(4 +- 7.5%) = (3.45 +- 8.9%) = (3.45 +- 0.3)m//s`