Forces and Pulleys of two blocks

In summary, the conversation discusses a physics problem involving two blocks connected by a rope and pulleys. The blocks have weights of 412N and 908N, respectively, and are massless with no friction. The conversation then asks for the acceleration of the lighter block and why the answers for this and a similar problem with the heavier block removed are different.
  • #1
Cheddar
38
0

Homework Statement


Two blocks are connected by a rope that passes over a set of pulleys. One block has a weight of 412N and the other has a weight of 908N. The rope and the pulleys are massless and there is no friction. (a) What is the acceleration of the lighter block? (b) Suppose that the heavier block is removed, and a downward force of 908N is provided by someone pulling on the rope. Find the acceleration of the remaining block. (c) Why are the answers in (a) and (b) different?

Homework Equations


weight = mass * acceleration(gravity)


The Attempt at a Solution


So mass = 42.0 kg for the smaller black and mass = 92.7 kg for the larger block.
This is as far as I get.
 
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  • #2
***NOT AN EXPERT***

If I were you, I would draw a force diagrams for each block. These kinds of problems can get really confusing if you don't sort out what forces are going where.
 
  • #3
Cheddar said:
Two blocks are connected by a rope that passes over a set of pulleys. One block has a weight of 412N and the other has a weight of 908N. The rope and the pulleys are massless and there is no friction. (a) What is the acceleration of the lighter block?

Hi Cheddar! :smile:

Call the tension T, do two F = ma equations, one for each block, and then eliminate T. :wink:
 

1. How do forces and pulleys affect the motion of two blocks?

Forces and pulleys play a major role in the motion of two blocks. When a force is applied to one of the blocks, it will cause both blocks to accelerate or move in the direction of the force. The pulley system will also help to distribute the force evenly between the two blocks, allowing for smoother motion.

2. What is the relationship between force and acceleration in a system of two blocks connected by a pulley?

According to Newton's Second Law of Motion, the force applied to an object is directly proportional to its acceleration. In a system of two blocks connected by a pulley, the force applied to one block will result in an equal force being applied to the other block. This means that the acceleration of both blocks will be the same.

3. How do you calculate the mechanical advantage of a pulley system?

The mechanical advantage of a pulley system is the ratio of the output force to the input force. To calculate it, you divide the weight of the load being lifted by the force applied to the rope. For a system with two blocks and one pulley, the mechanical advantage would be 2, as the force applied to the rope is divided between the two blocks.

4. What is the purpose of using multiple pulleys in a system of two blocks?

Adding multiple pulleys to a system of two blocks increases the mechanical advantage and reduces the amount of force needed to lift a load. This is because each additional pulley decreases the amount of force needed to support the load by half. Using more pulleys also allows for smoother and more controlled motion of the blocks.

5. Are there any other factors that can affect the motion of two blocks connected by a pulley?

Yes, there are several other factors that can affect the motion of two blocks connected by a pulley. These can include the mass and friction of the blocks, the angle and tension of the rope, and any external forces acting on the system. It is important to take all of these factors into consideration when analyzing the motion of any system involving forces and pulleys.

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