Block moving around in a semi cricle

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In summary: So you have to figure out the angle of the inclined plane.In summary, the problem involves a large block with a semi-circular hole and a small block inside positioned at a 25 degree angle. The surfaces are frictionless and there is a force applied to the large block. The goal is to find the force on the large block that causes the small block to move 25 degrees, as well as the force of the large block on the small block. To solve this, one must determine the forces acting on each block separately and use the equation F=ma. The force of gravity and the force of the large block on the small block must be considered. The force of the large block on the small block can be thought of
  • #1
arrax
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Homework Statement



A cylinder is cut out of a large block with mass M=4kg sitting on a table. A small block of negligible size and mass m=0.5kg is placed within the hole. All the surfaces are frictionless. The radius of the cut is R=0.80m and the angle is 25 degrees.

Basically there's a block with a semi-circle cut into it. Inside the semi circle is a block that is positioned 25 degrees to the left from bottom dead center. And there is a force F pushing this big block with a semi-circle cut to the right. So when you push the block, the little block in the half pipe moves. I'm supposed to find the FORCE on the big block that makes the small block move 25 degrees and the force of the block on the mass m (the small block)

Homework Equations



F=ma, Circumference = 2∏r

The Attempt at a Solution



i have no idea where to start, but for the small block i tried using tanθ = a/g, but I came out with 4.575 m/s^2 for my a which seems way too fast.
 
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  • #2
Start where one should always start: by writing down the forces acting on the blocks (separately). There are two on the small block: one is gravity and the other is ...
 
  • #3
The other is the M block acting on the small block, and So gravity does act on the small block so I do end up using tan25 deg = a/g I think because of the force of the big block acting on the small block on the x axis.
 
  • #4
Recall that the small block is very small. The force of the big block on the small will be the same as the force of an inclined plane tangent to the hole would be.
 
  • #5


I would approach this problem by first identifying the key variables and their relationships. The main variables in this problem are the masses of the two blocks (M and m), the radius of the semi-circle (R), the angle at which the small block is positioned (25 degrees), and the force applied to the large block (F).

To find the force on the big block that makes the small block move 25 degrees, we can use the equation F=ma, where F is the force we are looking for, m is the mass of the small block, and a is the acceleration of the small block.

To find the acceleration, we can use the formula for circular motion, a=v^2/r, where v is the velocity of the small block and r is the radius of the semi-circle. Since the small block is moving at a constant speed in a circular path, we can also use the formula for linear velocity, v=ωr, where ω is the angular velocity.

To find ω, we can use the relationship between linear and angular velocity, v=rω, where v is the linear velocity and r is the radius.

Putting these equations together, we can find the acceleration of the small block, and then use that to find the force on the big block.

To find the force of the big block on the small block, we can use Newton's third law, which states that for every action, there is an equal and opposite reaction. Therefore, the force of the big block on the small block will be equal in magnitude but opposite in direction to the force of the small block on the big block.

Overall, it is important to identify the key variables and their relationships in order to solve this problem. By using the appropriate equations and principles, we can find the forces on both blocks and understand the motion of the system.
 

1. What is a "Block moving around in a semi circle"?

A block moving around in a semi circle refers to an object that follows a curved path, resembling a half circle, while maintaining its orientation and shape. It can be observed in various systems, such as pendulums, satellites, and rotating objects.

2. What causes a block to move in a semi circle?

The motion of a block in a semi circle is caused by a centripetal force acting on the object, which constantly pulls it towards the center of the circular path. This force is directed perpendicular to the object's velocity and is necessary to maintain the curved motion.

3. How is the speed of a block moving in a semi circle related to its radius?

The speed of a block moving in a semi circle is inversely proportional to the radius of the circular path. This means that as the radius decreases, the speed increases, and vice versa. This relationship is described by the equation v = √(rω), where v is the speed, r is the radius, and ω is the angular velocity.

4. Can a block moving in a semi circle change its speed?

Yes, a block moving in a semi circle can change its speed by either increasing or decreasing the centripetal force acting on it. This can be achieved by altering the radius of the circular path or by changing the angular velocity of the object.

5. How does the mass of a block affect its motion in a semi circle?

The mass of a block does not affect its motion in a semi circle, as long as the centripetal force remains constant. However, a heavier block may require a greater force to maintain the curved motion compared to a lighter block, due to its greater inertia.

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