Physics

Problem

A ball is thrown vertically upward with a speed of

20\,\text{m/s}

from the ground. A branch of a tree is located

15\,\text{m}

above the ground. The ball passes the branch on the way up and again on the way down. Calculate the time interval between the two passings. Take

g = 10\,\text{m/s}^2

. a)

4\,\text{s}

1\,\text{s}

2\,\text{s}

3\,\text{s}