Acceleration of object with friction: Homework help

AI Thread Summary
To start sliding a 50 kg box with static friction coefficients of 0.70, a minimum force of 343 N is required. Once the box is in motion, the kinetic friction coefficient of 0.50 applies, which reduces the frictional force. The net force acting on the box after it starts sliding is not zero, leading to a non-zero acceleration. The acceleration can be calculated by subtracting the kinetic friction force from the applied force and using F=ma. Understanding the transition from static to kinetic friction is crucial for solving the problem correctly.
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A 50 kg box rests on the floor. The coefficients of static and kinetic friction are 0.70 and 0.50, respectively.
a.) What is the minimum force required to start the box sliding from rest?
b.) After the box starts sliding, the person continues to maintain that force. What is the acceleration of the box?

Homework Equations

: μ=Ff/mg Fnet=ma[/B]3. I solved part A by using the force of static friction and my answer was 343 N, but I can't figure out part B. I figured since the net force on my force diagram was zero and the box is sliding at a constant velocity, that the acceleration would be zero, but that isn't correct. Any ideas?
 
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APphysicsSenior said:
I figured since the net force on my force diagram was zero
The net force is zero only before it begins sliding. Once it starts sliding, what happens to the friction force?
 

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