Find the magnitude of a block pulling a 200 lb block

In summary, the conversation discusses finding the magnitude of a block being pulled up a plane with a given acceleration and coefficient of kinetic friction. The forces acting on the block in the direction of the incline need to be equal to its mass times its acceleration, while the forces perpendicular to the incline need to add up to zero. To solve the problem, the size of the pulling force on the block needs to be determined.
  • #1
the_d
127
0
Help Please!

I have to find the magnitude of a block pulling a 200 lb block up a plane of angle 30 degrees with an acceleration of 4.0425 ft/s^2, the coefficient of kinetic friction is 0.2. Where should I start?
 

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  • #2
The sum of all of the forces acting on the block in the direction of the incline need to be equal to its mass times its acceleration.
 
  • #3
ok so for the x and y direction EF = ma then what?
 
  • #4
ok so for the x and y direction EF = ma then what?
 
  • #5
You need to add the forces in the direction of the incline and divide them by the mass of the block to get the given acceleration.

The sum of the forces perpendicular to the incline need to add up to zero.
 
  • #6
ok i got those, so now how do i find? the weight of the block that's pulling? the only force on it is its (mass) * (gravity)
 
  • #7
There are at least four forces in operation!

The weight, friction, the required pulling force up the incline and the normal force.
 
  • #8
ok, thanks for ur help
 
  • #9
You first need to determine the size of the pulling force, [tex]P[/tex], on the block on the incline in order to solve the problem.
 

FAQ: Find the magnitude of a block pulling a 200 lb block

What is the formula for finding the magnitude of a block?

The formula for finding the magnitude of a block is force = mass x acceleration. In this case, the force is the weight of the block, which is 200 lbs, and the acceleration is the rate at which the block is being pulled.

How do I determine the mass of the block?

The mass of the block can be determined by dividing its weight (200 lbs) by the acceleration due to gravity (9.8 m/s²). This will give you the mass of the block in kilograms.

What units are used to measure the magnitude of the block?

The magnitude of the block is typically measured in Newtons (N), which is the unit for force. In this case, the weight of the block (200 lbs) can be converted to Newtons using the conversion factor 1 lb = 4.448 N.

How does the angle of the pull affect the magnitude of the block?

The angle of the pull affects the magnitude of the block by changing the direction of the force. The magnitude of the block will be the same, but the force will be applied in a different direction based on the angle of the pull. This can be taken into account by using trigonometric functions to calculate the components of the force in the x and y directions.

Can I use this method to find the magnitude of any block?

Yes, this method can be used to find the magnitude of any block as long as the weight and acceleration are known. However, the units may be different depending on the unit system used (e.g. pounds and feet per second squared in the imperial system, or kilograms and meters per second squared in the metric system).

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