If a rock is propelled upward from the surface of Mars at a velocity of 93 m/sec, it reaches a height
s = 93t – 1.86t^2 after t sec.
a. Find the rock’s velocity and acceleration at time t.
v'(t)=93-3.72t
a''(t)=-3.73
b. How long does it take the rock to reach its highest point?
v'(t)= 93-3.72t=0
t=25s
c. How high does the rock go?
f(x)= 93(25)-1.86(25)^2=1162.5m
I couldn't find the last two.
d. How long does it take the rock to reach 1/4 of its maximum height?
e. How long is the rock aloft?