Question

A man stands on the roof of a building of height 14.4 m and throws a rock with a velocity of magnitude 28.7 m/s at an angle of 29.9 ∘ above the horizontal. You can ignore air resistance.

a) the maximum height above the roof reached by the rock
b) Calculate the magnitude of the velocity of the rock just before it strikes the ground.
c) Calculate the horizontal distance from the base of the building to the point where the rock strikes the ground.

Answer 1

the height relative to the ground is
y = 14.4 + (28.7 sin29.9°)t - 4.9t^2
(a) find the vertex of the parabola
(b) find t when y=0; v^2 = ((28.7 sin 29.9°)-9.8t)^2 + ((28.7 cos29.9°)^2)
(c) x = (28.7 cos29.9°)t