12-85. The flight path of the helicopter as it takes off from A is defined by the parametric equations x = (2P) m and y= (0.041) m, where t is the time in seconds. Determine the distance the helicopter is from point A and the magnitudes of its velocity and acceleration when t=10 s.

A helicopter starts from rest at point A and travels along the straight-line path with a constant acceleration a. If the speed v = 32 m/s when the altitude of the helicopter is h = 38 m, determine the values of r, r, 0, and 0 as measured by the tracking device at O. At this instant, 0 = 43°, and the distance d = 182 m. Neglect the small height of the tracking device above the ground. Answers: !!! = = X = i i i i ע Th m/s m/s² rad/s rad/s² A

3. A race car C travels around the horizontal circular track that has a radius of 300ft. If the car increases its speed at a constant rate of 7ft/s², starting from rest, determine the time needed for it to reach an acceleration of 8ft/s². What is its speed at this instant? an r = 300 ft

4. Starting from rest, the motorboat travels around the circular path, p= 50-m, at a speed v = 0.8t m/s, where 't' is in seconds. Determine the magnitudes of the boat's velocity and acceleration when it has p- S0m traveled 20-m.