Answer:
[tex]\large \boxed{\text{C. 4 m/s}}[/tex]
Explanation:
At 5 s the body has travelled 10 m.
Between 5 s and 10 s, the body reached 30 m.
Distance travelled = 30 m - 10 m = 20 m
Time = 10 s - 5 s = 5 s
[tex]\text{Speed} = \dfrac{\text{ distance}}{\text{time}} = \dfrac{\text{20 m}}{\text{5 s}} = \textbf{4 m/s}\\\\\text{The average speed between 5 s and 10 s is $\large \boxed{\textbf{4 m/s}}$}[/tex]
