The displacement covered by a body in time `(5.0 +- 0.6) s is ( 40.4 +- 0.4 ) m`. Calculate the speed of the body . Also determine the percentage error in the speed.

Explanation

Here, `s = (40.0+- 0.4)m` and `t = (50.6 +- 0.6)s`
`:.` Speed `v = (s)/(T) = (40.0)/(5.0) = 8.0 ms^(-1)` As `v = (s)/(t)`
`:. (Delta v)/(v) = (Delta s)/(s) + (Delta t)/(t)`
Here `Delta s = 0.4m, s = 40.0m, Delta t = 0.6s, t = 5.0s`
`:. (Delta v)/(v) = (0.4)/(40.0) + (0.6)/(5.0) = 0.13`
`implies Delta v = 0.13xx8.0 = 0.04`
Hence, `v = (8.0 +- 1.04) ms^(-1)`
`:.` Percentage error `= ((Delta v)/(v) xx 100) = 0.13xx100 = 13%`