Step-by-step explanation:
The height of the swipe card is given by :
[tex]h(t)=-3t^2+15t+18[/tex] .....(1)
We need to find the maximum height of the swipe card and the time to reach the maximum height.
For maximum height, put dh/dt = 0
So,
[tex]\dfrac{d}{dt}(-3t^2+15t+18)=0\\\\-9t+15=0\\\\t=\dfrac{15}{9}\\\\t=1.67\ s[/tex]
It will take 1.67 seconds to reach the maximum height.
Now, put t = 1.67 s in equation (1).
[tex]h(1.67)=-3(1.67)^2+15(1.67)+18\\\\=34.68\ feet[/tex]
Hence, the maximum height of the swipe card is 34.68 feet and the time to reach this height is 1.67 s.
