A bullet is fired from a gun at the speed of $280\ \text{m s}^{-1}$ in the direction $30^\circ$ above the horizontal. The maximum height attained by the bullet is ($g = 9.8\ \text{m s}^{-2},\ \sin 30^\circ = 0.5$):
$H_{\max} = \dfrac{u^2 \sin^2\theta}{2g} = \dfrac{280^2 \times (0.5)^2}{2 \times 9.8} = 1000\ \text{m}$.