Why Do Three Blocks on a Frictionless Surface Accelerate at the Same Rate?

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In summary, the conversation discusses a problem where three blocks with different masses are placed on a frictionless surface and a horizontal force is applied to the first block. The question is to determine the acceleration and the forces of the normals between the blocks. The solution involves assuming that the acceleration is the same for all three blocks, which is justified by the fact that there is nothing to make the blocks accelerate at different rates.
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astrololo
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Homework Statement



On a surface without friction, we have 3 blocs with mass A=0,4 kg B=0,1 Kg C=0,3 Kg which are placed one beside the other, with A being first, B second and C third.. If we push on the bloc A with a horizontal force of 2,4 N, determine what is the acceleration and what are the forces of the normals which are located between the blocs.

http://imgur.com/F9PQwKK

Homework Equations



Sum force of x = m * a(x)

The Attempt at a Solution


I was able to resolve the problem and got the right answers. What I was wondering is why should I assume that the acceleration is going to be the same for the 3 blocs ? I was able to solve the problem because I assumed this to be true, but I don't know why it is. I guess that the fact there's no friction makes this true. any help ?
 
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Well, given the picture, B and C can't accelerate slower than A. There also is nothing that could make them accelerate faster.

Does that answer your question ?
 
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BvU said:
Well, given the picture, B and C can't accelerate slower than A. There also is nothing that could make them accelerate faster.

Does that answer your question ?
Said this way, it makes sense. Ty
 

Related to Why Do Three Blocks on a Frictionless Surface Accelerate at the Same Rate?

1. How does the weight of one block affect the movement of another block?

The weight of one block can affect the movement of another block by either increasing or decreasing the friction between the two blocks. If the weight of one block is greater than the other, it will create a larger normal force and increase the friction, making it harder to move. If the weight is evenly distributed, the blocks will have equal normal forces and the friction will be balanced, making it easier to move.

2. Can blocks with different shapes and sizes be pushed on one another?

Yes, blocks with different shapes and sizes can be pushed on one another. However, the shape and size of the blocks can affect the distribution of weight and the amount of friction between the blocks, which can impact the ease of movement. For example, a larger block with a wider surface area may create a larger normal force and more friction compared to a smaller block with a smaller surface area.

3. How does the surface material of the blocks impact their movement?

The surface material of the blocks can impact their movement by affecting the amount of friction between them. For example, blocks with rough surfaces will have a higher coefficient of friction compared to blocks with smooth surfaces, making it harder to move them. Additionally, the surface material can also affect the normal force between the blocks, which can impact their movement.

4. Can blocks push on one another without sliding?

Yes, blocks can push on one another without sliding if the force applied is not strong enough to overcome the static friction between them. This is known as static equilibrium, where the forces acting on the blocks are balanced and there is no movement. However, if the force applied is strong enough to overcome the static friction, the blocks will start to slide against each other.

5. How do external factors such as temperature and humidity affect the movement of blocks pushing on one another?

External factors such as temperature and humidity can affect the movement of blocks pushing on one another by altering the surface conditions of the blocks. For example, a higher temperature can cause the blocks to expand, changing their surface area and potentially increasing the friction between them. Similarly, high humidity can cause the blocks to absorb moisture and become more slippery, making it easier for them to slide against each other.

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