Solution
We find t by applying Equation to motion along the y axis (with v
y
=0 characterizing y=y
max
0=(12m/s)+(−2.0m/s
2
)t⇒t=6.0s.
Then, Equation applies to motion along the x axis to determine the answer:
v
x
=(8.0m/s)+(4.0m/s
2
)(6.0s)=32m/s.
Therefore, the velocity of the cart, when it reaches y=y
max
, is (32m/s)
i
^
.