Moderate -0.3 This is a straightforward projectiles question requiring knowledge that at maximum height the vertical component of velocity is zero, combined with standard SUVAT equations. The single-step calculation (using v² = u² + 2as or the maximum height formula) makes it slightly easier than average, though the setup requires understanding projectile motion concepts.
1 A stone is projected from a point on level ground with speed \(20 \mathrm {~m} \mathrm {~s} ^ { - 1 }\) at an angle of elevation of \(\theta ^ { \circ }\) above the horizontal. When the stone is at its greatest height it just passes over the top of a tree that is 17 m high. Calculate \(\theta\).
1 A stone is projected from a point on level ground with speed $20 \mathrm {~m} \mathrm {~s} ^ { - 1 }$ at an angle of elevation of $\theta ^ { \circ }$ above the horizontal. When the stone is at its greatest height it just passes over the top of a tree that is 17 m high. Calculate $\theta$.
\hfill \mbox{\textit{OCR M2 2009 Q1 [4]}}