Question

will it go? * 31 A rock is dropped from a treetop 19.6 m high, and then, 1.00 s later, a second rock is thrown down. With what initial velocity must the second rock be thrown if it is to reach the ground at the same time as the first?

Answer 1

First node u = 0 a = 9.80 h = 19.6 h = ut + 1/2 gt^2 = > 19.6 = 0 times t + 1/2 times 9.8 t^2 = > t^2 = 2 times 19.6/9.8 = 4 = > t = 25 Second rock h = 19.6 a = 9.8 t = 2 - 1 = 1 h = ut + 1/2 gt^2 = > 19.6 = u times 1 + 1/2 times 9.8 times 1^2 = u + 4.9 = > u = 19.6 - 4.9 = 14.7m/s = > u = 14.7m/s