Answer
a) At $t=0$ the snowboarder is 5 meters below the edge of the half-pipe.
b) She reaches the air after 0.4184 seconds and return to the pipe after 2.4387 seconds.
c) She spends $2.0203$ seconds in the air.
Work Step by Step
(a) At $t=0$ the snowboarder is 5 meters below the edge of the half-pipe.
b) Find the zeros of $y=-4.9 t^2+14 t-5$ using the quadratic formula:
$$
\begin{aligned}
& t=\frac{-14 \pm \sqrt{14^2-4(-4.9)(-5)}}{2(-4.9)} \\
& t=0.4184 \text { or } 2.4387
\end{aligned}
$$
She reaches the air after 0.4184 seconds and return to the pipe after 2.4387 seconds.
c) She spends $2.4387-0.4184=2.0203$ seconds in the air.
