Using the height function h=-16t^2+1450, determine the average rate of change of h with the respect to t over the given interval
a. 0< t< 1 b 1< t< 2

Just find the slope between those points 

0<t<1
t=0 and t=1

H(0)=1450
H(1)=1434
slope=(1434-1450)/(1-0)=(-16/1)=-16

1<t<2
t=1 and t=2
H(1)=1434
H(2)=1386
slope=(1386-1434)/(2-1)=-48/1=-48

in 0<t<1, average rate of change is -16
in 1<t<2, average rate of change is -48