Projectile Motion Homework: Finding Time, Distance, and Speed

AI Thread Summary
A rock is thrown horizontally from a bridge at 32.6 m/s from a height of 32.0 meters, resulting in an air time of 2.56 seconds and a horizontal distance of 83.31 meters to the impact point. The vertical motion is analyzed separately, with the initial vertical velocity being zero, as the rock is thrown horizontally. The final speed upon impact is determined by combining the horizontal and vertical components using the Pythagorean theorem. The discussion emphasizes the independence of horizontal and vertical velocities in projectile motion. The final speed calculation remains unresolved, with participants seeking clarification on the correct approach.
deaninator
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Homework Statement


A rock is thrown horizontally from a bridge at a speed of 32.6 m/s. If the rock is 32.0 meters above the river at the moment of release, find how long the rock is in the air? 2.56 seconds. Find the horizontal distance to the point of impact from the point of release? 83.31 meters
Find the speed with which the rock strikes the river? I don't know

Homework Equations


V=Sq root of(vx^2 + vy^2)
Vox = Vx
X=VoxT

Vy=Voy + at
y=voyt + 1/2at^2
Vy^2 = Voy^2 + 2ay




The Attempt at a Solution


MY HINT:Apparently this is a vector problem. "Add" horizontal and vertical velocities. So i added the horizontal velocity that was 32.6...but what's the vertical velocity?
 
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vx and vy are independent of each other. Considering only the y-direction, what can you say about the initial speed of the ball in that direction?
 
fss said:
vx and vy are independent of each other. Considering only the y-direction, what can you say about the initial speed of the ball in that direction?

Ok vertical velocity is 32.6 m/s...but how do i find the horizontal speed?
 
deaninator said:
Ok vertical velocity is 32.6 m/s...but how do i find the horizontal speed?

It's already given, neglecting air resistance. The speed at which the rock hits the ground will be the resultant vector of vx and vy.
 
fss said:
It's already given, neglecting air resistance. The speed at which the rock hits the ground will be the resultant vector of vx and vy.

If it is already given then what is it? Oh is it 12.5 m/s?
 
Last edited:
deaninator said:

Homework Statement


A rock is thrown horizontally from a bridge at a speed of 32.6 m/s.

There you go.
 
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