Galileo had dropped 1 of the rocks 0.5s b4 the other.

Question

what's the velocity of the 2nd rock for them 2 land at the same time.

the distance is 55m.

Answer 1

Is air resistance's negligible?

Hey dude if you really want to learn do it yourself and use these formulations.

For constant acceleration:

x(t) = x0 + v0t + 1/2at^2

v(t) = v0 + at

vf^2 - vi^2 = 2a(xf - x0)

where x0 is the initial position

xf is the final position

v0 is the initial velocity

vf is the final velocity

a is the acceleration

And yeah remember the initial velocity for both is 0.

Answer 2

55 m = 1/2 Gt^2

55 m = 1/2 9.8 m/s/s x t^2

t^2 =11.22

t  = 3.35 sec

V1 = 9.8 x 3.35 m/s = 33 m/sec

V2 = 9.8 x 2.85 m/s + initial velocity (thrown down and affected by the same gravity)

V2 = 27.9 m/s + initial velocity

55 m = 1/2 9.8 2.85^2 + init velocity x 2.85

55 = 39.8 + init veolicity x 2.85

15.1998 = Init velocity x 2.85

Init velocity = 6.1 m/s

V2 = 27.9 + 6.1 = 34 m/s