Halliday, Resnick & Walker — Motion in Two and Three Dimensions: Problem 94

Curtain of death. A large metallic asteroid strikes Earth and quickly digs a crater into the rocky material below ground level by launching rocks upward and outward. The following table gives five pairs of launch speeds and angles (from the horizontal) for such rocks, based on a model of crater formation. (Other rocks, with intermediate speeds and angles, are also launched.) Suppose that you are at \(x = 20 \text{ km}\) when the asteroid strikes the ground at time \(t = 0\) and position \(x = 0\) (Fig. 4.32). (a) At \(t = 20 \text{ s}\), what are the \(x\) and \(y\) coordinates of the rocks headed in your direction from launches A through E? (b) Plot these coordinates and then sketch a curve through the points to include rocks with intermediate launch speeds and angles. The curve should indicate what you would see as you look up into the approaching rocks. Launch Speed (m/s) Angle (degrees) A 520 14.0 B 630 16.0 C 750 18.0 D 870 20.0 E 1000 22.0