Pulley problem: find equilibrium

In summary, the problem is to find the force that will allow a system with masses of 10kg and 20kg at a 40 degree angle to move at a constant speed on a frictionless plane. The solution involves using Newton's second law.
  • #1
bebeoshea
1
0
Pulley Problem.

m1=10kg and m2=20kg both at angle 40 degrees.Find the force, parallel to the frictionless plan.e that will allow the systme to move at constant speed.

I would know how to solve this problem if it wasn't constant speed.but it being that just through me off.All i want is a start off.thanks in advanced.

oshea
 
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  • #2
bebeoshea said:
Pulley Problem.

m1=10kg and m2=20kg both at angle 40 degrees.Find the force, parallel to the frictionless plan.e that will allow the systme to move at constant speed.

I would know how to solve this problem if it wasn't constant speed.but it being that just through me off.All i want is a start off.thanks in advanced.

oshea

Look up Newton's second law and see what happens to the net force acting on a system when the speed is constant.
 
  • #3
123,

To find the force required to keep the system moving at a constant speed, we need to consider the forces acting on each mass. The first thing we need to do is draw a free body diagram for each mass. This will help us visualize the forces acting on each mass and their directions.

For mass m1, we have the force of gravity (mg) acting downwards, and the tension force (T1) acting upwards at an angle of 40 degrees from the horizontal. Similarly, for mass m2, we have the force of gravity (2mg) acting downwards, and the tension force (T2) acting upwards at an angle of 40 degrees from the horizontal.

Since the system is at equilibrium, the net force on each mass must be zero. This means that the vertical components of the tension forces (T1 and T2) must be equal to the force of gravity acting on each mass (mg and 2mg). This can be represented by the following equations:

T1sin40 = mg
T2sin40 = 2mg

We can solve for T1 and T2 by dividing both equations by sin40 and substituting the values for m1 and m2:

T1 = (10kg)(9.8m/s^2)/sin40 = 155.6 N
T2 = (20kg)(9.8m/s^2)/sin40 = 311.2 N

Now, to find the force parallel to the frictionless plane that will keep the system moving at a constant speed, we need to consider the horizontal forces. Since there is no friction, the only horizontal force is the component of the tension force (T1cos40 and T2cos40) acting in the direction of motion. This can be represented by the following equation:

F = T1cos40 + T2cos40

Substituting the values for T1 and T2, we get:

F = (155.6 N)cos40 + (311.2 N)cos40 = 349.4 N

Therefore, the force parallel to the frictionless plane that will keep the system moving at a constant speed is 349.4 N.
 

1. What is a pulley?

A pulley is a simple machine made up of a wheel with a groove around its circumference, and a rope or cable that runs through the groove. It is used to lift or move objects by reducing the amount of force needed to lift the object.

2. How do you find the equilibrium in a pulley system?

To find the equilibrium in a pulley system, you must first calculate the total weight of all the objects on either side of the pulley. Then, you must determine the direction of the forces acting on the pulley. Finally, you can use the formula W1 x D1 = W2 x D2, where W1 and W2 are the weights on each side of the pulley, and D1 and D2 are the distances from the pulley to the object, to find the equilibrium point.

3. What are the different types of pulley systems?

There are three types of pulley systems: fixed, movable, and compound. In a fixed pulley, the pulley is attached to a stationary object and the load is lifted by pulling on the rope. In a movable pulley, the pulley is attached to the load and moves along with it. A compound pulley combines both fixed and movable pulleys to create a mechanical advantage, making it easier to lift heavy objects.

4. What factors affect the equilibrium in a pulley system?

The equilibrium in a pulley system can be affected by the weight of the objects on each side of the pulley, the direction and angle of the forces acting on the pulley, and the type of pulley system being used. Other factors such as friction and the condition of the pulley can also play a role in determining the equilibrium point.

5. Can a pulley system ever be in equilibrium if the weights on each side are not equal?

Yes, a pulley system can still be in equilibrium even if the weights on each side are not equal. This is because the equilibrium point is determined by the distance of the weights from the pulley rather than their actual weights. As long as the weights are positioned at the correct distance, the system will be in equilibrium.

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