Grade 11 Physics: Projectile Motion Calculations

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    Grade 11 Physics
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To solve the projectile motion problem, the key is to recognize that the time the bullet is in the air is determined solely by its vertical motion, not its horizontal speed. The bullet falls from a height of 2.0 meters, and the time can be calculated using the free fall formula, which is derived from the equations of motion. The horizontal speed of 325 m/s does not affect the time of flight. Understanding this distinction clarifies the approach to finding the solution. The problem ultimately simplifies to a free fall calculation.
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Homework Statement



Ok, well I have a Grade 11 Physics question regarding Projectile Motion Calculations. The question is: A bullet is shot horizontally from a gun. If the bullet's speed exiting the muzzle is 325 m/s and the height of the gun above the ground is 2.0m,

a) how long was the bullet in the air?


The Attempt at a Solution



I see that a) is looking for the time. As well as, I have 325 which I assume is the velocity and 2.0m which I assume is the distance. Now this is the part I am stuck on. Which formula do I use to find Time? Sorry if my question seems stupid. I'm just in need for some help.

Thanks
 
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Think about what the problem is asking you. Does the time it takes for the bullet to fall vertically depend on how fast it is moving horizontally?
 
fss said:
Think about what the problem is asking you. Does the time it takes for the bullet to fall vertically depend on how fast it is moving horizontally?

Hmm ... well I guess it would? Sorry I'm a physics noob.
 
nope it doesnt. it just depends on vertical direction...now do you get a clue?
 
It is basically a free fall problem.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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