2. A rocket test projectile is launched skyward at 88 m/sec (198 mi/hr). How high does it go? v o = ? v final = ? a = ? time to reach peak, t = ? height reached, x = ? When does it peak? What has happened by that point? v = 0 = 9 sec So = 792m – 396.9m = 395 m (1/4 mile)  9.8 m/sec 2  8 m/sec

3. A ball is thrown straight upward and caught when it returns to the height from which it was released. 1. At its peak position, the ball’s A. instantaneous velocity is maximum. B. instantaneous velocity is zero. C. instantaneous acceleration is zero. D. both B & C are true. 2. The time to fall back from its peak position is A. greater than B. equal to C. less than the time it took to climb that high. 3. The speed it builds up to downward by the moment it is caught is A. greater than B. equal to C. less than the speed it was thrown upward with.

4. For objects for which air friction is negligible, time up = time down speed down = speed up

5. Two spheres of identical mass are Released when the mechanism above Is triggered. One sphere is launched Horizontally by a spring, the other is simultaneously dropped from rest. A. The launched sphere will reach the ground first. B. Both spheres touch ground at the same time. C. The dropped sphere reaches the ground first.

6. Galileo’s critics argued that if the earth moved:

9. A stone is flung horizontally at 8 m/sec from a point 1100 meters above the base of a cliff. How far away from the cliff does it land? or +1100m + 9.80m/s Careful!!! Actually a y =  9.8m/s 2 a x = ? 0 VERTICALLY t = 15 sec HORIZONTALLY  x = 120 m Its y-component of motion is like dropping from rest!

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11. WeightSupport (floor)

12. Adding all these supporting forces together some pull left, some pull right, some pull forward, some pull back all tend to pull UP! (a tug-of-war balancing)

13. Styrofoam bridge weighted at center Pressure applied to rigid glass bar