Question

The acceleration due to gravity near the surface of Mars is 3.72ms^-2 . A
rock is thrown straight up from the surface with an initial velocity
of 23ms^-2 . How high does it go?

Answer 1

a = -3.72
v = -3.72t + c
when t = 0, v = 23
so c = 23

v = -3.72t + 23
s = -1.86t^2 + 23t + k , where s is the height
when t = 0 , s = 0, so k = 0

max of s is obtained when v = 0
3.72t = 23
t = 23/3.72 = 2300/372 = 575/93

when t = 575/93
s = .... use your calculator
I got appr 71.1 m

check my above arithmetic

Answer 2

The answer is supposed to be 213.31m as from your calculations you only considered the first part leaving out 23(575/93)