Calculate Position & Acceleration Vectors of Bird in xy-Plane

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The discussion focuses on calculating the position and acceleration vectors of a bird flying in the xy-plane, defined by the velocity vector v(t) = (a-bt^2)i + ctj. The position vector r(t) can be derived by integrating the velocity function, while the acceleration vector is obtained by differentiating the velocity function. Participants express confusion about whether to substitute constants a, b, and c before integration and the specific form required for the position vector. The altitude of the bird as it crosses x=0 is determined by focusing on the y-component of the position vector, indicating that the bird's motion is vertical at that point. Overall, the calculations emphasize the relationship between position, velocity, and acceleration in the context of the bird's flight.
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A bird flies in the xy-plane with a velocity vector given by v(vector) = (a-bt^2)(i-vector) + ct (j-vector) , with a= 2.4m/s, b=1.6m/s^3,c=4.0m/s^2. The positive y-direction is vertically upward. At t=0 the bird is at the origin.

Calculate the position vector of the bird as a function of time.
Express your answer in terms of a, b, and z. Write the vector r(t) in the form vector(r(t)x,r(t)y , , where the x and y components are separated by a comma.

Calculate the acceleration vector of the bird as a function of time. also in the form as stated above.

What is the bird's altitude (y-coordinate) as it flies over x=0 for the first time after t=0?
 
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I see, good standard questions... :rolleyes:

Let's see how you are tackling them!
 
Well, atiderviative will give me the position vector, but I don't know if I should plug in the values of a, b, etc. prior to me taking the antiderivative. Also I am not sure what form they are talking about.

For the acceleration the derivative is needed.

Not sure about the last question
 
a, b, c are constants.

For the last question look at the position function, what can you notice?
 
I notice that x=0, so there is no horizontal motion. What do they mean by birds altitude as it flies over x=0 after t=0, meaning whent t=1. Also so since x=0 I only focus on the y componet of the position vector, which is (ct^2)/2?
 
Look at the acceleration vectorial function, it's x component is negative, so sooner or later the bird will pass the straight line x=0.
 
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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