Physics

Problem

The position

x

of a motorcyclist travelling along a straight road is recorded at three instants as follows: at

t = 0\,\text{s}

x = 2\,\text{m}

; at

t = 4\,\text{s}

x = 38\,\text{m}

; and at

t = 9\,\text{s}

x = 128\,\text{m}

. a. (i) Calculate the average velocity during the first

4\,\text{s}

. b. (ii) Calculate the average velocity during the next

5\,\text{s}

(from

t = 4\,\text{s}

t = 9\,\text{s}

). c. (iii) Determine the average velocity for the entire interval from

t = 0\,\text{s}

t = 9\,\text{s}

and express your answer also in

\text{km h}^{-1}