What forces are acting on a block suspended by a rope over a pulley?

Click For Summary

Homework Help Overview

The discussion revolves around a physics problem involving forces acting on a block suspended by a rope over a pulley. The scenario includes a block resting on a frictionless surface and another block suspended, with a focus on understanding the forces and tension in the system.

Discussion Character

  • Exploratory, Conceptual clarification, Problem interpretation, Assumption checking

Approaches and Questions Raised

  • Participants discuss the free body diagrams for both the block on the surface and the suspended block, questioning the forces acting in both the x and y directions. There is an attempt to apply Newton's second law and clarify the role of tension and gravitational forces.

Discussion Status

Some participants are exploring the correct identification of forces and their directions, while others are questioning their previous attempts at drawing free body diagrams. Guidance has been offered regarding the identification of forces acting on the blocks.

Contextual Notes

There is mention of previous mistakes in drawing free body diagrams, and participants are encouraged to reconsider the forces involved, particularly in the y direction for the suspended block.

mybrohshi5
Messages
365
Reaction score
0

Homework Statement



A light rope is attached to a block with mass 4.40 kg that rests on a frictionless, horizontal surface. The horizontal rope passes over a frictionless, massless pulley, and a block with mass m is suspended from the other end. When the blocks are released, the tension in the rope is 18.5 N

Homework Equations



f=ma
Newtons 2nd law

The Attempt at a Solution



T - m(g) = ma

18.5 - 4.4(9.8) = 4.4(a)

a = 5.59

This is wrong?

Help please!

thank you :)
 
Physics news on Phys.org
mybrohshi5 said:

Homework Statement



A light rope is attached to a block with mass 4.40 kg that rests on a frictionless, horizontal surface. The horizontal rope passes over a frictionless, massless pulley, and a block with mass m is suspended from the other end. When the blocks are released, the tension in the rope is 18.5 N

Homework Equations



f=ma
Newtons 2nd law

The Attempt at a Solution



T - m(g) = ma

18.5 - 4.4(9.8) = 4.4(a)

a = 5.59

This is wrong?

Help please!

thank you :)
I gather you are trying to find the acceleration of the blocks...when you draw a free body diagram of the block on the table, what are the forces acting on the block in the X direction? Then use F_x_net = ma
 
i had to draw 2 free body diagrams for the first 2 parts of the assignment for the 4.4 kg mass and the unknown mass but i got them both wrong... :(

but the forces in the x direction acting on the block of mass 4.4 kg would be the tension and that is it right?
 
mybrohshi5 said:
i had to draw 2 free body diagrams for the first 2 parts of the assignment for the 4.4 kg mass and the unknown mass but i got them both wrong... :(

but the forces in the x direction acting on the block of mass 4.4 kg would be the tension and that is it right?
Right. That's the only force acting in the x direction. Ther are also forces in the y direction, 2 of them in the y direction. Can you identify them and their directions?
When you draw free body diagrams, identify all the forces acting. The force of gravity is usually one of them, acting down toward the center of the earth. This is an 'action at a distance' force; almost all other forces in Physics 101 are contact forces...there must be a contact between 2 surfaces or particles or objects in order for there to be a force.
 

Similar threads

  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 18 ·
Replies
18
Views
2K
  • · Replies 38 ·
2
Replies
38
Views
5K
  • · Replies 22 ·
Replies
22
Views
2K
Replies
6
Views
2K
Replies
13
Views
4K
  • · Replies 8 ·
Replies
8
Views
4K
  • · Replies 25 ·
Replies
25
Views
6K
  • · Replies 21 ·
Replies
21
Views
11K