Find friction coefficient given initial and final velocity

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To find the coefficient of friction given initial and final velocities and distance traveled, one can use the principles of kinematics and dynamics. The problem involves a box sliding on a surface where it decelerates due to friction, transitioning from 4.56 m/s to 3.33 m/s over 0.700 m. Calculating the acceleration using the kinematic equation can help determine the net force acting on the box, which includes friction. A free-body diagram is essential to visualize the forces and identify known and unknown variables. Understanding these concepts will aid in solving this specific problem and similar ones in the future.
tyger2020
I am not sure how to approach a problem involving the friction coefficient when only given initial velocity, final velocity, and distance traveled. I could combine the friction and kinematic equations, but I am only familiar with doing that for one velocity...

Here is the specific problem I had trouble with:

A cardboard box of unknown mass is sliding upon a mythical frictionless surface.

The box has a velocity of 4.56 m/s when it encounters a bit of friction. After sliding 0.700m, the box has a velocity of 3.33 m/s.

What is the coefficient of friction of the surface?

How do I solve this problem in particular, and what is the general procedure to solve problems like this?
 
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When you use the homework template, it allows us to clearly see the problem statement, and what you know, and what you have tried.

Look at what information you have, and what you are able to calculate from the information (acceleration, perhaps?) Could that be of assistance here? What information do you need, in order to calculate friction?
 
tyger2020 said:
How do I solve this problem in particular, and what is the general procedure to solve problems like this?
What equations for motion under constant acceleration have you been taught?
 
tyger2020 said:
what is the general procedure to solve problems like this?

In addition to those equations for motion, you also want to draw a free-body diagram detailing all the forces acting on the box, in addition to identifying and listing your variables. What are your known variables? Which variables do you not know? Which variable must you find?
 
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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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