The average rate of change of height is
[tex]\frac{\Delta H}{\Delta t}[/tex]
(a).
From 0 seconds to 2.3 seconds
[tex]\Delta t=2.3s-0s=2.3s[/tex]
and
[tex]\Delta H=92m-0m=92m[/tex]
Therefore,
[tex]\frac{\Delta H}{\Delta t}=\frac{92m}{2.3s}=\textcolor{#FF7968}{\frac{40m}{s}}[/tex]
(b).
From 4.6 seconds to 11.5 seconds we have
[tex]\Delta t=11.5s-4.6s=6.9s[/tex]
and
[tex]\Delta H=0m-138m=-138m[/tex]
Therefore,
[tex]\frac{\Delta H}{\Delta t}=\frac{-138m}{6.9s}=\textcolor{#FF7968}{\frac{-20m}{s}}[/tex]
Hence, (a). 40m/s and (b). -20m/s.
