Nowadays, Etna volcano, in the East Coast of Sicily (Italy), is one of the world's most active volcano. It ejects hot rocks and lava, out in the air. A large rock is ejected from the volcano's crater Bocca Nuova with an initial speed of $45.0 \mathrm{~m} / \mathrm{s}$, at an angle of $60^{\circ}$ above the horizontal, as shown in the picture on the right. The rock hits the ground $65.0 \mathrm{~m}$ lower than its starting point. The air resistance is negligible.
- What are the horizontal and vertical component of the initial velocity vector $\vec{v}_0$ ?
- What is the maximum height the rock reaches above the ground?
How much time does the rock spend in the air?
[22.5 m/s; $39.0 \mathrm{~m} / \mathrm{s} ; 142.6 \mathrm{~m} ; 9.38 \mathrm{~s}$ ]