Friction and tensions with two blocks on a string on an incline

In summary, two blocks, one with a mass of 16 kg and the other with a mass of 8 kg, are connected by a string over a frictionless, massless pulley. The blocks are released from rest on an inclined plane at an angle of 37 degrees with a coefficient of kinetic friction of 0.23. The acceleration of the blocks is 4 m/s2 and the tension in the string is 92.8 N. The tension is the same throughout the string.
  • #1
rnien
4
0

Homework Statement


Two blocks are connected by a string over a frictionless, massless pulley such that one is resting on an inclined plane and the other is hanging over the top edge of the plane. the hanging block has a mass of 16 kg and the one on the plane has a mass of 8 kg. the coefficient of kinetic friction between the block and the inclined plane is 0.23. the blocks are released from rest.
Edit: The incline is at an angle of 37 degrees.

a. what is the acceleration of the blocks?
b. what is the tension in the string connecting the blocks?

Homework Equations


Ffr=Coefficient x Fn
A= Fnet / Mass

The Attempt at a Solution


I solved for the Fgx and the Fgy using cos and sine. I got Fgx= 47.18 N, and for Fgy= 62.6 N. I solved for Force of friction using equations above and got 14.4 N. Also I found the Fg for the 16 kg block to be 156.8. So I found Fnet of the whole system = 95.22. Divided by mass of 24 gives an acceleration of 4 m/s2 (I think ?)

For tension, so far I have figured the tension of the string of just the 16 kg block to be 92.8 N ? Not sure where to go now..
 
Last edited:
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  • #2
It seems that you're doing it right, but what's the angle of inclination of the plane? You seem to have forgotten to tell us this.
 
  • #3
Oops, sorry, the incline is at an angle of 37 degrees.
 
  • #4
Then I think your calculations are fine.
 
  • #5
Okay thank you! But is my tension right? I found tension for the string above the hanging block to be 92.8 N but I'm confused as to if I have to add anything to this? or the tension is the same throughout the string??
 

Related to Friction and tensions with two blocks on a string on an incline

1. What is friction?

Friction is a force that resists the relative motion between two surfaces in contact. It is caused by the irregularities on the surfaces and the intermolecular forces between them.

2. How does friction affect the movement of two blocks on a string on an incline?

Friction between the blocks and the incline will act in the opposite direction of the movement, making it more difficult for the blocks to slide down the incline. This will cause a decrease in the acceleration of the blocks and a change in their velocity.

3. What factors affect the amount of friction in this scenario?

The amount of friction between the blocks and the incline depends on the types of surfaces in contact, the force pressing the surfaces together, and the roughness of the surfaces. It also depends on the angle of the incline and the weight of the blocks.

4. How can friction be reduced in this scenario?

Friction can be reduced by using smoother surfaces, decreasing the force pressing the surfaces together, or by adding a lubricant between the surfaces. In the case of the incline, reducing the angle of the incline can also decrease the amount of friction.

5. What is the relationship between friction and tension in this scenario?

In this scenario, the tension in the string connecting the two blocks will be affected by the amount of friction between the blocks and the incline. If there is a high amount of friction, the tension in the string will also increase as the blocks try to resist sliding down the incline. If there is less friction, the tension in the string will decrease.

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