Coefficient of Kinetic Friction physics

[Chaoticsouls]

Homework Statement

Physics problem - coefficient of friction? Bonnie and Clyde are sliding a 300 kg bank safe across the floor to their getaway car. The safe slides with a constant speed if Clyde pushes from behind with 385 N of force while Bonnie pulls foward on a rope with 350N of force. What is the safe's coefficient of kinetic friction of the bank floor?

Homework Equations

I'm guessing f=ma?

The Attempt at a Solution

2.0x10? What I did was use the formula and drew out the picture and tried to solve the problem. I ended up getting confused on which formula to use and how to go about solving it.

 

[drpizza]

Nope, that's not the correct formula. How would you find the coefficient of friction using a formula that doesn't even mention the coefficient of friction? There's a formula for the force due to friction that has something to do with the coefficient of friction. Look for that formula. Also, the problem mentions "constant velocity" - what do you know about constant velocity?

 

[Moetasim]

Dear Bonnie and Clyde,

Thank you for your interesting problem. In order to find the coefficient of kinetic friction, we can use the formula f = μkN, where f is the force of friction, μk is the coefficient of kinetic friction, and N is the normal force exerted on the safe by the floor.

To solve this problem, we first need to find the normal force. Since the safe is sliding at a constant speed, we know that the forces acting on it must be balanced. This means that the force of friction must be equal in magnitude and opposite in direction to the combined force of Clyde and Bonnie. So, we can set up the following equation:

f = 385 N + 350 N = 735 N

Next, we can use the formula for force of friction to find the normal force:

f = μkN

735 N = μk(300 kg * 9.8 m/s^2)

N = 2.45x10^3 N

Now, we can plug this value for N back into the original equation to solve for μk:

f = μkN

735 N = μk(2.45x10^3 N)

μk = 0.3

Therefore, the coefficient of kinetic friction for the bank floor is 0.3.

I hope this helps with your getaway plans. Just remember to always account for friction in your heists.

Best of luck,