Need Help with Two Blocks & Rope Physics Problem

In summary, the conversation discusses a problem involving two blocks connected by a rope and a force of 50 N acting on a 5 kg mass at an angle of 36 degrees. The questions asked are: what is the normal force on the 5 kg mass, and what is the acceleration of the blocks and the tension in the rope. The individual is unsure if their answer of 15.55 N for the normal force is correct and is seeking clarification and the formulas used to solve the problem. They also request for a picture of the physical arrangement of the blocks and for their work to be posted, not just their answers.
  • #1
Cougar1112
9
0
Ok I am new this forum so hello to all. Here is the problem that I've been working on. Is this right or wrong and what is the right answer?


Two blocks are connected by a rope that wraps around a pulley. A force of 50 N acts on the 5 kg mass at an angle of 36 degrees.

1. what is the normal force on the 5kg mass?(I got 15.55 N)
2. what is the acceleration of the blocks and the tension in the rope?(2.6 m/s squared for acceleration, but I can't figure out the tension)


Im sure I got this question wrong so that's why I am using this board. Also can someone post up the formulas that they used to solve this problem.

THANKYOU!
 
Physics news on Phys.org
  • #2
Please describe the physical arrangement of the blocks in more detail (a picture would help). Also: Post your work, not just your answers.
 
  • #3


Hello and welcome to the forum! It's great that you are seeking help and clarification on this problem. Based on the information provided, here is how I would approach this problem:

1. To find the normal force on the 5kg mass, we can use the formula F = ma, where F is the force, m is the mass, and a is the acceleration. In this case, the force acting on the mass is the weight (mg) and the acceleration is due to gravity (9.8 m/s^2). So the normal force would be 5kg x 9.8 m/s^2 = 49 N. This means that the 50 N force is balanced by the normal force, so the 5kg mass is not moving up or down.

2. To find the acceleration of the blocks and the tension in the rope, we can use the formula F = ma again. This time, the force acting on the blocks is the tension in the rope, and the acceleration is the same for both blocks since they are connected by the rope. So we have the equation T = (5kg + 2kg) x a. We also know that the force of 50 N is acting on the 5kg mass at an angle of 36 degrees, so we need to find the component of this force that is acting in the direction of motion. This can be done by using the formula Fcos(theta), where F is the force and theta is the angle. So in this case, the component of the force acting in the direction of motion is 50 N x cos(36 degrees) = 40.6 N. Therefore, we have the equation T = (5kg + 2kg) x a = 40.6 N. Solving for a, we get a = 40.6 N / 7kg = 5.8 m/s^2. This is the acceleration of both blocks.

To find the tension in the rope, we can plug in the value for the acceleration (5.8 m/s^2) into the equation T = (5kg + 2kg) x a. This gives us T = 7kg x 5.8 m/s^2 = 40.6 N. So the tension in the rope is 40.6 N.

I hope this helps! In terms of formulas, the key ones used here are F = ma and Fcos
 

FAQ: Need Help with Two Blocks & Rope Physics Problem

What is the problem statement?

The problem involves two blocks connected by a rope, with one block resting on a horizontal surface and the other hanging off the edge. The goal is to determine the tension in the rope and the acceleration of the system.

How do I approach solving this problem?

First, draw a free-body diagram for each block to identify all the forces acting on them. Then, write out the equations of motion for each block and combine them to eliminate any unknown variables. Finally, solve for the remaining variables using algebra or calculus.

What assumptions can I make for this problem?

Some common assumptions for this type of problem are: the rope is massless, the pulley or surface is frictionless, and the system is in equilibrium or moving at a constant velocity. It is important to state any assumptions made in your solution.

Can I use specific values for the masses and lengths of the blocks and rope?

Yes, the problem should provide specific values for the masses and lengths of the blocks and rope. If not, you can assign variables and solve for the variables in terms of the given parameters.

Are there any helpful tips for solving this type of problem?

Yes, it can be helpful to draw a diagram and label all the forces, use proper sign conventions for directions, and double-check your calculations for accuracy. It is also recommended to practice similar problems and familiarize yourself with the equations and concepts involved.

Similar threads

Replies
10
Views
2K
Replies
18
Views
721
Replies
25
Views
4K
Replies
38
Views
3K
Replies
5
Views
2K
Replies
15
Views
2K
Replies
37
Views
782
Back
Top