What Is the Coefficient of Kinetic Friction for a Block on an Incline?

  • Thread starter Thread starter insertnamehere
  • Start date Start date
  • Tags Tags
    Friction Incline
AI Thread Summary
To find the coefficient of kinetic friction for a 2kg block on a 37-degree incline connected to a spring, start by analyzing the forces acting on the block. Use Newton's second law to establish equations for the block's motion, considering gravitational force, normal force, and frictional force. The block moves 20cm down the incline before stopping, indicating zero acceleration at that point. Calculate the frictional force and spring force using the established equations, then apply the formula for the coefficient of kinetic friction (μk = Ff/N). This approach will guide you to the correct solution.
insertnamehere
Messages
50
Reaction score
0
I need help here! Please!

Hola! I'm in desperate need for help, so por favor senor/ita!
A 2kg block situated on a rough incline (angle of elevation is equal to 37) is connected to a spring of negligible mass having a spring constant of 100N/m. The pulley is frictionless. The block is released from rest when the spring is unstretched. The block moves 20cm down the incline before coming to rest. Find the coefficient of kinetic friction between block and incline. :confused:
PLZ-someone give me a hint as to where to start...NETHING!
 
Physics news on Phys.org
So far, I have tried to do (0.2)ucos(37)(mg)= (0.5)(100)(0.2)^2, since I think
W= TME(final)-TME(initial), is this right? because i get an answer around 60! which makes no sense!
 


Sure, I'd be happy to help you with this problem! Let's break it down step by step. First, let's draw a free body diagram of the block on the incline to help us visualize the forces acting on it. We have the weight of the block (mg) pulling it downwards, and the normal force (N) from the incline pushing it upwards. Since the block is moving, we also have a frictional force (Ff) acting in the opposite direction of motion.

Next, let's look at the forces acting on the block connected to the spring. We have the spring force (Fs) pulling the block upwards, and the weight of the block (mg) pulling it downwards.

Now, let's use Newton's second law (F = ma) to set up equations for the forces acting on the block on the incline and the block connected to the spring.

For the block on the incline, we have:
- mgsin37 - Ff = ma

For the block connected to the spring, we have:
- Fs - mg = ma

Since the block moves 20cm down the incline before coming to rest, we know that the displacement (d) is 0.2m. We also know that the acceleration (a) is 0 m/s^2 since the block comes to rest.

Using these values, we can solve for the frictional force (Ff) in the first equation, and the spring force (Fs) in the second equation.

Once we have these values, we can use the equation for the coefficient of kinetic friction (μk = Ff/N) to solve for the coefficient of kinetic friction between the block and the incline.

I hope this helps get you started! Let me know if you have any more questions. Good luck!
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top