Solving Physics Problem: Find a_2 of 2 Blocks, 2 Pulleys

In summary: T))))/m_1In summary, the problem involves a system of two blocks connected by a massless string and two pulleys, with one block sliding on a frictionless table and the other attached to a wall. The magnitude of the acceleration of the block of mass m_1 can be calculated using Newton's second law and is expressed as a_1 = T/m_1, where T is the tension in the string and m_1 is the mass of the block.
  • #1
nat2007
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A block of mass m_1 is attached to a massless, ideal string. This string wraps around a massless pulley and then wraps around a second pulley that is attached to a block of mass m_2 that is free to slide on a frictionless table. The string is firmly anchored to a wall and the whole system is frictionless.

1.Given the magnitude a_1 of the acceleration of the block of mass m_1 , find a_2 , the magnitude of the horizontal acceleration of the block of mass.

So I figured out that a_2=((m_1*g)-T)/m_1 ...

2. Calculate a_1, the magnitude of the acceleration of the block mass m_1. Write an expression for a_1. Express the acceleration magnitude a_1 in terms of m_1, m_2, and g.
 

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  • #2


To calculate a_1, we can use Newton's second law, which states that the net force on an object is equal to its mass multiplied by its acceleration. In this case, the only forces acting on the block of mass m_1 are its weight (m_1*g) and the tension in the string (T). Therefore, we can write the following equation:

m_1*a_1 = m_1*g - T

Since we know the value of T from the first part of the problem, we can substitute it into the equation:

m_1*a_1 = m_1*g - ((m_1*g)-T)

Simplifying this, we get:

m_1*a_1 = m_1*g - m_1*g + T

m_1*a_1 = T

Now, we can substitute the expression for T from the first part of the problem:

m_1*a_1 = ((m_1*g)-T)

Substituting in the value of T, we get:

m_1*a_1 = ((m_1*g)-((m_1*g)-T))

Simplifying this, we get:

m_1*a_1 = T

Therefore, the expression for a_1 in terms of m_1, m_2, and g is:

a_1 = ((m_1*g)-((m_1*g)-T))/m_1

Now, we can plug in the value of T from the first part of the problem:

a_1 = ((m_1*g)-((m_1*g)-((m_1*g)-T)))/m_1

Simplifying this, we get:

a_1 = ((m_1*g)-(m_1*g)+T)/m_1

a_1 = T/m_1

Substituting in the value of T, we get:

a_1 = ((m_1*g)-((m_1*g)-((m_1*g)-((m_1*g)-T))))/m_1

a_1 = ((m_1*g)-(m_1*g)+T)/m_1

a_1 = T/m_1

Therefore, the magnitude of the acceleration of the block of mass m_1 is:

a_1 = ((m_1*g)-((m_1*g)-((m_1*g)-((m
 
  • #3


To calculate a_1, we can use Newton's second law of motion, which states that the net force on an object is equal to its mass multiplied by its acceleration (F=ma). In this case, the only force acting on the block of mass m_1 is the tension in the string, which is equal to the weight of the block (m_1*g). Therefore, we can write the equation as m_1*a_1 = m_1*g, and solving for a_1 gives us a_1 = g. This means that the magnitude of the acceleration of the block of mass m_1 is equal to the acceleration due to gravity, and does not depend on the mass of the block or the second block.
 

1. How do I calculate the acceleration (a_2) of the two blocks in a 2-pulley system?

To calculate the acceleration of the two blocks in a 2-pulley system, you will need to use the formula a_2 = (m_1*g - m_2*g)/(m_1 + m_2), where m_1 and m_2 are the masses of the two blocks and g is the acceleration due to gravity (usually 9.8 m/s^2). This formula takes into account the weight of the blocks and the tension in the pulleys.

2. What is the difference between a fixed pulley and a movable pulley in this problem?

In this problem, a fixed pulley is attached to a stationary object and only changes the direction of the force being applied. A movable pulley, on the other hand, is attached to one of the blocks and changes both the direction and magnitude of the force being applied due to the tension in the rope. This difference affects the acceleration of the two blocks.

3. How is the tension in the rope related to the acceleration of the blocks?

The tension in the rope is directly related to the acceleration of the blocks. In fact, the tension is what causes the blocks to accelerate. As one block moves down, the other block moves up and the rope experiences a tension that is equal to the weight of the two blocks combined. This tension is what drives the acceleration of the blocks.

4. What assumptions are made when solving this type of problem?

When solving a physics problem involving a 2-pulley system, some assumptions are made in order to simplify the problem. These assumptions include: negligible friction in the pulleys and between the rope and pulleys, no mass of the rope is considered, and the rope is assumed to be inextensible (does not stretch).

5. Is there a limit to the number of pulleys that can be used in this type of problem?

No, there is no limit to the number of pulleys that can be used in this type of problem. However, as the number of pulleys increases, the complexity of the problem also increases. It is important to carefully consider the system and make appropriate assumptions in order to accurately solve the problem.

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