Answer:
Reaches a maximum height of 235.00 feet in 3.75 seconds.
Step-by-step explanation:
The height of the boulder, h, in feet after t seconds is given by the function is given by :
[tex]h=-16t^2+120t+10[/tex] .....(1)
For maximum height, put [tex]\dfrac{dh}{dt}=0[/tex]
i.e.
[tex]\dfrac{d(-16t^2+120t+10)}{dt}=0\\\\-32t+120=0\\\\32t=120\\\\t=3.75\ s[/tex]
Put t = 3.75 in equation (1). So,
[tex]h=-16(3.75)^2+120(3.75)+10\\\\h=235\ \text{feet}[/tex]
So, the boulder's maximum height is 235 feets and it takes 3.75 s to reach to its maximum height.