Physics Kinematics in One Dimension

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The discussion revolves around solving a kinematics problem involving a 1000kg weather rocket launched vertically. The rocket experiences constant acceleration for the first 16 seconds, after which it coasts to an altitude of 5100m at 20 seconds. Participants debate whether sufficient information is provided to determine the rocket's acceleration and speed. The importance of deriving the speed after the initial acceleration phase is emphasized as a critical step in solving the problem. The conversation highlights the need for clear expressions and calculations in kinematics to arrive at the correct answers.
aeubz
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Wow... I'm fried from doing this problem... Any help would be nice...

A 1000kg weather rocket is launched straight up. The rocket motor provides a constant acceleration for 16s, then the motor stops. The rocket altitude 20s after launch is 5100m. You can ignore any effects of air resistance.
a) What was the rocket's acceleration during the first 16s?
b) What is the rocket's speed as it passes through a cloud 5100m above the ground.

My work is scanned... (#7 circled)

Personally, I think not enough info is given..
 

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There is enough info.

What have you tried so far?

Have you got an expression for the speed of the rocket after 16 seconds?
 
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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