Question

A stone is dropped into a river from a bridge 43.9m above thewater. Another stone is thrown vertically down 1.00s afterthe first is dropped. Both stones strike the water at thesame time. What is the initial speed of the secondstone?

Answer 1

Below

Step-by-step explanation:

Find time of first stone to strike water ....second stone take 1 s less

First stone

d = 1/2 a t^2

43.9 = 1/2 (9.81)(t^2) shows t = ~ 3 seconds

Second stone

d = vo t + 1/2 a t^2

43.9 = vo (t) + 1/2 (9.81) t^2 t = 3 -1 = 2 seconds

43.9 = vo (2) + 4.905 (2)^2

shows vo = 12.1 m/s