Problem 1

A ball is launched horizontally from height

h=20\,\mathrm m

u=15\,\mathrm{m/s}

above level ground. Neglect air resistance and take

g=10\,\mathrm{m/s^2}

. Horizontal motion is uniform and vertical acceleration is downward. (a) Find the first requested quantity. (b) Find the second quantity. (c) Determine the final result and check its (a) Find the flight time. (b) Find the horizontal range. (c) Find the impact speed and its angle below horizontal.

problems.proof.stepOf

problems.proof.prevStep problems.proof.nextStep

v_x=15,\quad v_y=gt=20\,\mathrm{m/s}

problems.proof.analysis

Rearranging the governing relation isolates the first requested result. Keeping the signs explicit also checks that its direction and magnitude are physically sensible.