Physics

Problem

A student wants to launch a ball from street level onto the flat roof of a nearby building. The roof is

15\,\text{m}

higher than the launch point and is horizontally

40\,\text{m}

away. If the ball is launched at

45^{\circ}

above the horizontal and air resistance is negligible, what is the minimum initial speed required for the ball to just reach the roof? a)

19\,\text{m\,s}^{-1}

25\,\text{m\,s}^{-1}

32\,\text{m\,s}^{-1}

35\,\text{m\,s}^{-1}