Answer:343 m
Step-by-step explanation:
Given
launch velocity of object is [tex]u=28\ m/s[/tex]
height of Platform [tex]h=336\ m[/tex]
height of object is given by
[tex]s(t)=-7t^2+14t+336[/tex]
For maximum height velocity of object is zero
i.e. [tex]\frac{ds}{dt}=0[/tex]
[tex]\frac{ds}{dt}=-14t+14+0=0[/tex]
[tex]t=\frac{14}{14}=1\ s[/tex]
Therefore after 1 sec object achieves maximum height
[tex]s(1)=-7(1)+14(1)+336[/tex]
[tex]s(1)=343\ m[/tex]