Question

A stone is dropped from the edge of a roof. How long does it take to fall 4.9 m? How fast does it move at the end of that fall?

Answer 1

Answer:

a. 1second

b. 9.8m/s

Explanation:

intital velocity of object is zero

using Newton's second equation of motion for gravity

s=ut+1/2gt²

4.9=0*t+1/2*9.8t²

4.9=4.9t²

t=1second

using Newton's first equation of motion

v=u+gt

v=0+9.8*1

v=9.8m/s