A trebuchet was a hurling machine built to attack the walls of a castle under siege. A large stone could be hurled against a wall to break apart the wall. The machine was not placed near the wall because then arrows could reach it from the castle wall. Instead, it was positioned so that the stone hit the wall during the second half of its flight. Suppose a stone is launched with a speed of v0=28.0 m/s and at an angle of u0 = 40.0°.What is the speed of the stone if it hits the wall (a) just as it reaches the top of its parabolic path and (b) when it has descended to half that height? (c) As a percentage, how much faster is it moving in part (b) than in part (a)?

Problem 12: Mt. Asama, Japan, is an active volcano complex. In 2009, an eruption threw solid volcanic rocks that landed far from the crater. Suppose that one such rock was launched at an angle of 0 = 52.3 degrees above horizontal, and landed a horizontal distance d = 850 m from the crater, and a vertical distance h = 620 m below the crater. Part (a) Write and expression for vo, the initial speed of the rock in terms of 0, d, and h. Expression : Vo = Select from the variables below to write your expression. Note that all variables may not be required. cos(a), cos(4), cos(0), sin(a), sin(), sin(0), ß, y, 0, d, g, h, m, n, P Part (b) What is the initial speed of the rock in m/s? Numeric :A numeric value is expected and not an expression. Vo = Part (c) How long, in seconds, was the rock in the air? Numeric :A numeric value is expected and not an expression. t =

A ball is thrown vertically upward with an initial speed of 88 ft/sec from the base A of a cliff with H = 60 ft. Determine the distance h by which the ball clears the top of the cliff and the time t after release for the ball to land at B. Also, calculate the magnitude of the impact velocity vg. Neglect air resistance and the small horizontal motion of the ball. Answers: h = i ft t = i sec VB = i ft/sec