the royal Gorge Bridge in Colorado rises 321 m above the Arkansas river. suppose you kick a rock horizontally off the bridge. The magnitude of the Rock's horizontal displacement is 45.0 m. Find the speed at which the rock was kicked

2.48 m/s

Explanation:

We can use the kinematic equation,

s = ut + ½at²

Where

s = displacement

u = initial velocity

t = time taken

a = acceleration

Using the equation in vertical direction,

321 = 0*t + ½*g*t², u = 0 because initial vertical velocity is 0

We get t = 8.01 s

Using the equation in the horizontal direction,

52 = u*8.01 + ½*0 * (8.01) ²,. a = 0 because no unbalanced force act on object in that direction

So u = 2.48 m/s