How Long Does a Ball Take to Hit the Ground from a 12.5m Building?

AI Thread Summary
To determine how long it takes for a ball to hit the ground from a 12.5m building, the vertical motion must be analyzed separately from the horizontal motion. The initial vertical speed of the ball when it leaves the building is zero, and it accelerates downward due to gravity. Using the kinematic equation for vertical motion, the time can be calculated based on the height of the building. Additionally, to find the range from the base of the building, the horizontal speed of 3.4m/s must be considered, although an angle is not necessary for this calculation. Understanding these components is essential for solving the problem accurately.
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Physics 12 Kinematics Question.. Please Help!

Homework Statement


A ball rolls off the top of a 12.5m building with a speed of 3.4m/s. How long does it take to hit the ground? What is the range from the base of the building?


Homework Equations


V = V0 + at
V2=V02 + 2ad
Avg V = (V = V0) /2
d = V0 + 1/2 at2


The Attempt at a Solution


All I've got was a sketch drawn.. Please help me. Well I timed 12.5 by 3.4 to get how long it took to hit the ground but I'm not sure if it is right. I'm guessing to find the range you must need an angle of some sort?
 
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jameo15 said:

Homework Statement


A ball rolls off the top of a 12.5m building with a speed of 3.4m/s. How long does it take to hit the ground? What is the range from the base of the building?


Homework Equations


V = V0 + at
V2=V02 + 2ad
Avg V = (V = V0) /2
d = V0 + 1/2 at2


The Attempt at a Solution


All I've got was a sketch drawn.. Please help me. Well I timed 12.5 by 3.4 to get how long it took to hit the ground but I'm not sure if it is right. I'm guessing to find the range you must need an angle of some sort?
Welcome to PF jameo15,

You need to consider the horizontal and vertical components of motion separately. When the ball rolls off the building, just at the point where it leaves the surface, what is it's vertical speed?
 


Would it's vertical speed be the acceleration due to gravity? But at the point where it leaves the surface, it should be zero right?
 


jameo15 said:
Would it's vertical speed be the acceleration due to gravity?
No, but that would be it's acceleration.
jameo15 said:
But at the point where it leaves the surface, it should be zero right?
Correct. So using this information, can you determine how long it takes to hit the ground (just considering vertical motion).
 

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