Question

8. A stone is dropped from the edge of a roof.
a. How long does it take to fall 4.9m?
b. How fast does it move at the end of that fall?
c. What will be its acceleration after 1 second and after 2 seconds?

Answer 1

Hope this attachment will help you out..

Answer 2

Answer:

h = 19.6 m

u = 0

h = u t + 1/2 g t * t

19.6   = 0 + 1/2 * 9.8 * t * t            as  g = 9.8 m/s/s

t = 2 sec.    it takes 2 sec.

acceleration is always the same : g = 9.8 m/sec

velocity / speed at t = 2 sec is  =  u + g  t  = 0 + 9.8 * 2 sec = 19.6 m/sec