How Do You Calculate Tension and Acceleration in a Pulley System?

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In summary, to determine the tension and accelerations of the blocks attached to cords, give the lengths of the cords letters and use the equation F=ma to eliminate variables and solve for the desired values.
  • #1
myoplex11
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Homework Statement


Determine the tension developed in the cords attached to each block and the accelerations of the blocks. Neglect the mass of the pulleys and cords. I have attached the picture below.


Homework Equations


Fnet=ma


The Attempt at a Solution



W=mg=(6*9.8)
I have no idea how to proceede any further
 

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  • #2
… give the lengths names …

Hi myoplex11! :smile:

The first thing to do is to give the lengths of the cords letters, such as a and b.

I haven't seen the picture yet, so I don't even know if there's two blocks, but I assume a + b is a constant, so you can call that c, and then eliminate b by putting b = c - a.

Then you use your F = mx´´ equation to get an equation in a´´. :smile:
 
  • #3


As a scientist, it is important to approach problems systematically and use the appropriate equations and principles to find a solution. In this case, we can use the concept of Newton's Second Law, F=ma, to solve for the tension in the cords and the accelerations of the blocks.

First, we need to draw a free body diagram for each block, considering all the forces acting on them. The forces acting on the top block are its weight (mg), the tension in the cord attached to it (T1), and the tension in the cord attached to the bottom block (T2). Similarly, the forces acting on the bottom block are its weight (mg), the tension in the cord attached to it (T2), and the normal force from the ground (N).

Next, we can apply Newton's Second Law to each block separately. For the top block, we have Fnet = ma, where Fnet is the net force acting on the block and a is its acceleration. We can write this as:

T1 - T2 = ma1

Similarly, for the bottom block, we have:

T2 - mg = ma2

Since both blocks are connected by the same cord, the tension in the cord (T2) will be the same for both blocks. We can use this fact to solve for T2 by substituting the value of T2 from the second equation into the first equation:

T1 - ma2 - mg = ma1

Now, we can solve for T1 by using the values of m, a1, and a2 from the given information. Once we have the value of T1, we can substitute it into the second equation to solve for T2.

Finally, we can use the values of T1 and T2 to solve for the accelerations of the blocks by rearranging the equations and solving for a1 and a2.

In conclusion, by using the principles of Newton's Second Law and drawing free body diagrams, we can solve for the tension in the cords and the accelerations of the blocks in this problem involving pulleys. It is important to approach problems systematically and use the appropriate equations and principles to find a solution.
 

1. What are pulleys used for?

Pulleys are simple machines that are used to change the direction of a force or to lift heavy objects. They consist of a wheel with a grooved rim and a rope or belt that runs over the wheel. Pulleys are commonly used in cranes, elevators, and other lifting devices.

2. How do pulleys work?

Pulleys work by distributing the weight of an object over multiple ropes or cables, reducing the amount of force needed to lift the object. As the rope is pulled, the pulley rotates, allowing the weight to be lifted in a different direction than the applied force.

3. What are the different types of pulleys?

There are three main types of pulleys: fixed, movable, and compound. Fixed pulleys are attached to a surface and change the direction of the force, while movable pulleys are attached to the object being lifted and reduce the amount of force needed. Compound pulleys are a combination of fixed and movable pulleys, allowing for greater mechanical advantage.

4. What is mechanical advantage in relation to pulleys?

Mechanical advantage is a measure of how much a machine multiplies the force put into it. In relation to pulleys, mechanical advantage is determined by the number of ropes supporting the load. The more ropes used, the greater the mechanical advantage and the easier it is to lift a heavy object.

5. What are some real-life applications of problem involving pulleys?

Pulleys are used in many everyday situations, such as raising and lowering flags, opening and closing blinds, and in exercise equipment. They are also essential in larger scale applications, such as construction, transportation, and manufacturing industries. Pulleys are also commonly used in physics experiments to demonstrate principles of force and motion.

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