Q1. A rock is thrown directly upward from the edge of the roof of a building that is 50 m meters tall. The rock misses the building on its way down, and is observed to strike the ground 4.00 seconds after being thrown. Take the g the acceleration due to gravity is magnitude 9.80 m/s2 and neglect any effects of air resistance. What speed was the initial speed of the rock?
Q2. A package is dropped from a helicopter moving upward at 15 m/s. If it takes 16s before the package strikes the ground, the acceleration of gravity g = 9.8m/cm2 downward.
(a) How high above the ground was the package when it was released? Neglect air resistance.
Q3. A child sits on a merry-go-round, 1.5 meters from the center. The merry-go-round is in UCM uniform circular motion turning at a constant angular speed, the child is observed to have a radial (centripetal) acceleration of 2.4 m/s2 at this distance from the axis.
(a) Detemine the angular speed in radian/sec, then
(b) Determine how long does it take for the merry-go-round to make one revolution?
Q4. A stone is thrown upward with initial velocity 7.50 m/s at an angle of 42.0° above the horizontal from the upper edge of a cliff, and it hits the ground 1.50 s.
(a) Find the x and y components Vx and Vy of its velocity V just before it reaches the gound at t=1.5 s
(b) Then determine the magnitude Vof its velocity vector V just as it reaches the ground.
Q5. A projectile returns to its original height after 4.08 seconds, during which time it travels 76.2 meters horizontally. Determine what was the projectile's initial speed? (Use g = 9.80 m/s2)