Kinetic and Static Friction Problems

AI Thread Summary
To solve the friction problems, first calculate the acceleration of the plate using the distance and time given. With the mass of the plate at 250g, apply Newton's second law (F=ma) to find the force of friction. The magnitude of the frictional force can then be used to determine the coefficient of kinetic friction by dividing the frictional force by the normal force. A free-body diagram can help visualize the forces acting on the plate. Understanding the relationship between force, mass, and acceleration is crucial for solving these problems effectively.
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Kinetic and Static Friction Problems Please Help!

Mr. Bob slid a 250g plate 1.35m across the dish return counter. It slowed with a constant acceleration for 0.85s before coming to a stop.


a) Find the magnitude of the force of friction

b) What is the coefficient of kinetic friction between the plate and the counter?

(I have no idea how to do a. but if I have a. I'll know b.)
 
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What is the relationship between force, mass, and acceleration? You know the mass and the acceleration, so you can calculate the force using that relationship.
 


I know that is the direction I have to go but the answer has been alluding me. Could you please show me how to get the magnitude of friction!
 


Have you drawn a free-body diagram for the plate?
Look at the forces in the x-direction (only friction), and use Newtons's second law.
Have you calculated the (constant) acceleration of the plate?
 

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