With what speed does the rock hit the bottom?
A rock released from rest to fall on a small airless planet falls #y=g t^2# m in #t# sec, #g# a constant. Suppose that the rock falls to the bottom of a crevasse #"20 m"# below and reached the bottom in #"4 sec"# .
With what speed does the rock hit the bottom?
A rock released from rest to fall on a small airless planet falls
With what speed does the rock hit the bottom?
1 Answer
Oct 17, 2017
5 m/s
Explanation:
also on a small airless planet, the second movement law say:
therefore, knowing y = 20 m and t= 4 s I can calculate the aceleration:
now from the first law we have