What are the Forces Acting on a Block Pushed Against a Wall with Friction?

  • Thread starter Thread starter AtlBraves
  • Start date Start date
  • Tags Tags
    Friction
AI Thread Summary
The discussion revolves around analyzing the forces acting on a block pushed against a wall with friction. A horizontal force of 12 N is applied to a block weighing 6.0 N, with static and kinetic friction coefficients provided. Participants express confusion about determining the y-component of the forces and the overall force exerted by the wall. Key forces identified include the weight of the block acting downward and friction opposing the applied force. The conversation highlights the challenges of understanding the problem due to complex textbook explanations and communication barriers with the professor.
AtlBraves
Messages
11
Reaction score
0
This problem is giving me trouble. The x-component is -12i, but I don't know how to find the y-component. Can anyone tell me what the forces acting on the block are?

A 12 N horizontal force F pushes a block weighing 6.0 N against a vertical wall (Figure 6-25). The coefficient of static friction between the wall and the block is 0.65, and the coefficient of kinetic friction is 0.45. Assume that the block is not moving initially.

06_24.gif


(b) In unit-vector notation, what is the force exerted on the block by the wall?
 
Physics news on Phys.org
Well, if this were a block in a horizontal plane how would you indicate the force of friction relative to motion? Also if this were a block just sitting on a horizontal plane what forces would be acting and in which directions?
 
To be honest, I don't know. I can barely understand my professor because of his accent, and my book is useless because it is written in a very complex manner with examples that don't have anything to do with the problems given. I have no idea how to do over half of the problems on the homework assignment and I am dreading the next exam.
 
Ask yourself, does the block has mass? Yes so there's weight force, The wall is being pushed against has friction with the block?? yes, so the there's friction pointing against movement. Those are your forces on the y-axis.

Now you found what were the forces on the x-axis because the force applied to the block is horizontal. Consider for the Wall force a vector in its components.
 
Last edited:
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Back
Top