Is the Friction Force Determined by a Suspended Mass and Cart Movement?

[PhysicsAdvice]

1. If a cart is being pulled from rest by over 75cm in 2s by a suspended mass of 100g attached to the cart via a rope and pulley, what is the friction of the surface?



2. My question is whether the fapp force is the suspended mass. I know I need
Ff= μFN, Fn= -(fappy+Fg) and to get acceleration I'll need d=vit+0.5at^2, is this correct so far? and is the suspended mass indeed the fapp?

 

[PhanthomJay]

1. If a cart is being pulled from rest by over 75cm in 2s by a suspended mass of 100g attached to the cart via a rope and pulley, what is the friction of the surface?



2. My question is whether the fapp force is the suspended mass.

No, the suspended mass is accelerating, so the tension force applied to the cart (and acting on the suspended mass) is not the same as the weight of the suspended mass.

I know I need
Ff= μFN, Fn= -(fappy+Fg) and to get acceleration I'll need d=vit+0.5at^2, is this correct so far? and is the suspended mass indeed the fapp? [/b]

Your problem statement is missing information, such as the mass of the cart. Please present the problem as written.

 

[PhysicsAdvice]

I apologize, the mass of the cart is 75g, what would the firs step in solving this be?

if M=mass of cart and m=mass of suspended mass, could (M+m)x a + Ff= mxg work? Then solve for a since I have enough and then solve for Ff?

 

[PhanthomJay]

I apologize, the mass of the cart is 75g, what would the firs step in solving this be?

if M=mass of cart and m=mass of suspended mass, could (M+m)x a + Ff= mxg work?

Yes, it will work, but why?? You must draw free body diagrams of each mass and apply Newton's laws.

Then solve for a since I have enough and then solve for Ff?

You've got to determine the acceleration first based on the given information of displacement and time. Then solve for the friction force.