Calculating KE, PE & Total Energies: A 10kg Block & Friction

AI Thread Summary
The discussion revolves around calculating the kinetic energy (KE), potential energy (PE), and total energy of a 10 kg block sliding with an initial speed of 5 m/s and a friction coefficient of 0.5 after sliding 2.0 m. Participants emphasize the importance of calculating the force of kinetic friction and applying the work-energy theorem to determine the work done over the distance. The work done by friction will lead to a change in the block's energy and speed. The initial confusion about incorporating friction into the KE equation is addressed by focusing on how to calculate the work done. Understanding these concepts is crucial for solving the problem effectively.
bradefeld
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Homework Statement


Initially, a 10 kg block is sliding along the floor at a speed of 5 m/x. The coefficient of friction between the block and the floor is 0.5.

What are the KE, PE and total energies of the block after sliding 2.0 m?
What is the block's speed after sliding 2.0 m?

I don't recall how to apply friction to velocity in order to do the KE equation.


Homework Equations





The Attempt at a Solution

 
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f_k=\mu_kn
f_k is the force of kinetic friction. This number will be very important to you proceeding.
\mu_k is the coefficient of kinetic friction
n is the normal force
 
Yes, we found the friction force. Now how do we use that amount to figure out the energies and the final velocity?
 
Welcome to PF!

Yitzach said:
f_k=\mu_kn
f_k is the force of kinetic friction. This number will be very important to you proceeding.
\mu_k is the coefficient of kinetic friction
n is the normal force


Yitzach, you must stop making these unhelpful comments in homework threads.
bradefeld said:
I don't recall how to apply friction to velocity in order to do the KE equation.

Hi bradefeld! Welcome to PF! :smile:

You'll need to use the work-energy theorem … work done = change in energy.

So … what is the work done after 2.0 m ? :wink:
 

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