Mechanic about wood block, friction and pulley

In summary, two objects, A and B, weighing 50 N and 80 N respectively, are connected by a light string over a fixed pulley. The coefficient of sliding friction between A and the table surface is μ = 0.3, while the friction between the string and the pulley is neglected. To find the velocity of B after falling downwards for 2m, we use the formula v = √(2gh), where g = 10 ms^-2 and h = 2m. Plugging in the values, we get v = 2√2, which is the final answer.
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Homework Statement


Two objects A and B weighing 50 N and 80 N respectively were connected by a light string over a fixed pulley. A was put on a reasonably long and horizontal table surface. The coefficient of sliding friction between A and the table surface is μ = 0.3 while the friction between the string and the pulley is neglected. Find the velocity of B after falling downwards for 2m. (Take g = 10 ms^-2)
Wa = 50 N
Wb = 80 N
μ = 0.3



The Attempt at a Solution


The question given that the object B falls when at start, thus when object B falls the tension change as the angle change, can't even start the 1st equation.
 

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any1 can help?? i still can't figure how to do this, this question is past year exam question but there's only answer provided. the ans is 2√2
 

1. What is a wood block?

A wood block is a solid piece of wood, typically rectangular in shape, that is used for various purposes such as building, crafting, or as a tool.

2. How does friction affect a wood block?

Friction is the force that resists the motion of two surfaces in contact with each other. In the case of a wood block, friction can affect the movement of the block by either increasing or decreasing its speed depending on the surface it is in contact with.

3. What is the role of a pulley in mechanics?

A pulley is a simple machine that consists of a wheel with a grooved rim and a rope or belt that runs along the groove. It is used to change the direction of a force and can also be used to lift heavy objects by applying less force.

4. How does a pulley reduce the effort needed to lift an object?

A pulley reduces the effort needed to lift an object by distributing the weight of the object over multiple ropes or belts, making it easier to lift the object with less force. This is known as mechanical advantage.

5. How can a wood block, friction, and pulley be used together in a practical application?

One example of using a wood block, friction, and pulley together is in a simple machine called a block and tackle. This machine uses a combination of pulleys and a wood block to lift heavy objects with less effort. The friction between the ropes and pulleys also helps to keep the ropes in place and prevent them from slipping.

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