What is the difference between above and below the horizontal?

AI Thread Summary
The discussion clarifies the distinction between angles measured above and below the horizontal in projectile motion. When an object is thrown at an angle above the horizontal, such as 35 degrees, it has a positive vertical component, while an angle below the horizontal indicates a negative vertical component. In the given example, the apple core is thrown at 35 degrees above the horizontal, meaning the angle is indeed 35 degrees, not 55 degrees. Angles are always measured from the horizontal line, with horizontal motion being zero degrees. Understanding these concepts is essential for solving related physics problems accurately.
kitkat87
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Homework Statement


Some of the questions in my homework list the velocity either above or below the horizontal. I am confused as to what the difference is.

This is the question:

"A child sitting in a tree throws his apple core from where he is perched (4.0 m high) with a with a velocity of 5.0 m/s [35 DEG above the horizontal], and it hits the ground right next to his friend.

Does that mean it's a 35 DEG angle or does it mean its a 55 DEG angle?

Homework Equations

The Attempt at a Solution

 
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kitkat87 said:

Homework Statement


Some of the questions in my homework list the velocity either above or below the horizontal. I am confused as to what the difference is.

This is the question:

"A child sitting in a tree throws his apple core from where he is perched (4.0 m high) with a with a velocity of 5.0 m/s [35 DEG above the horizontal], and it hits the ground right next to his friend.

Does that mean it's a 35 DEG angle or does it mean its a 55 DEG angle?

Homework Equations

The Attempt at a Solution


Imagine a horizontal line is drawn from the child extending outward.

As the child throws the apple core at an angle above the horizontal, there is a vertical component of the velocity which is positive upward.

If the core is thrown at an angle below the horizontal, the vertical component of the velocity is negative downward toward the ground.

Angles are measured using the horizontal line as the reference, so something which is thrown horizontally has an angle of zero degrees.
 
Thank you for clarifying :)
 
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