Solve Equilibrium Problems with Frictionless Pivot & Find Upward Reaction Force

[noapologies01]

ive been trying to figure this stupid **** out the last 2 days and i can't get an answer..searched all over the internet..im sure its simple but i need to know how to do it..step by step..i already have the answers i just need to know how to get them..so please don't say do it this way n that's it..please word it and do step by step so i can understand..

fig. MC2 shows a uniform 100-cm long bar of weight F w, balanced in equilibrium on a frictionless pivot. [picture a long bar and it being balanced on the point, but the point is towards the beginning of the bar with a weight to the left of it, to keep it at equilibrium]
________________
(________________)
(w) ^

w=weight, ^= pivot

i know the weight of the bar acts 50 cm to the right of the pivot.

Q: what is the value of the upward reaction force on the bar at the pivot?
a. F w
b. 2F w
c. 3F w
d. 4F w

F w(weight)

Q2: what is the value of the load hanging at the left of pivot?
a. F w
b. 2F w
c. 3F w
d. 4F w

no clue how they got the numbers in front of the Fw

also..
how do i find an upward reaction force?

also..
different question: the motionless beam in the photo is 55 cm long and is supported at a frictionless pivot..if each of the 2 hanging objects on the left weighs 1.0N, how much does the clay way. ( a picture shows the 2 hanging objects on one side is heavier than the clay(which is high in the air).. i know the answer is 1.0 N but what's the equations

please help..i got instant messenger if better

 

[Nate810]

..Answer:Q: what is the value of the upward reaction force on the bar at the pivot?Answer: b. 2F wSince the bar is in equilibrium, the sum of all forces should be equal to 0. The bar is supported by two forces, the weight (Fw) of the bar and the upward reaction force (Fr). Therefore, Fw + Fr = 0. Since Fw = -Fr, Fr = 2Fw. Q2: what is the value of the load hanging at the left of pivot?Answer: b. 2F wSince the bar is in equilibrium, the sum of all forces should be equal to 0. The bar is supported by two forces, the weight (Fw) of the bar and the load (Fl) hanging on the left of the pivot. Therefore, Fw + Fl = 0. Since Fw = -Fl, Fl = 2Fw. how do i find an upward reaction force?To find the upward reaction force, you need to calculate the sum of all forces acting on the bar. Since the bar is in equilibrium, the sum of all forces should be equal to 0. The bar is supported by two forces, the weight (Fw) of the bar and the upward reaction force (Fr). Therefore, Fw + Fr = 0. Solving for Fr, we get Fr = -Fw. This means that the upward reaction force is equal in magnitude but opposite in direction to the weight of the bar. different question: the motionless beam in the photo is 55 cm long and is supported at a frictionless pivot..if each of the 2 hanging objects on the left weighs 1.0N, how much does the clay way. ( a picture shows the 2 hanging objects on one side is heavier than the clay(which is high in the air).. i know the answer is 1.0 N but what's the equationsTo find the weight of the clay, you need to calculate the sum of all forces acting on the clay. Since the beam is in equilibrium, the sum of all forces should be equal to 0. The beam is supported by three forces, the weight (Fc) of the clay, the load (Fl) hanging on the left

 

[ogb p]

..

I understand your frustration and I am happy to help you solve these equilibrium problems. First, let's go over some key concepts that will help you understand and solve these types of problems.

1. Frictionless pivot: A frictionless pivot means that the pivot point is smooth and there is no resistance or friction at that point. This allows the bar to rotate easily around the pivot.

2. Equilibrium: In order for an object to be in equilibrium, the net force and the net torque acting on it must be equal to zero. This means that the object is not moving and is balanced.

3. Reaction force: In this context, the upward reaction force is the force exerted by the pivot point on the bar to keep it in equilibrium. This is also known as the normal force.

Now, let's apply these concepts to the first question. We know that the weight of the bar is acting 50 cm to the right of the pivot. This means that the center of mass of the bar is 50 cm to the right of the pivot. In order for the bar to be in equilibrium, there must be an equal and opposite force acting at the pivot point. This is the upward reaction force, which is equal to the weight of the bar (Fw). Therefore, the answer to the first question is a. Fw.

For the second question, we need to use the concept of torque. Torque is the product of force and the distance from the pivot point. In this case, the load hanging on the left side of the pivot has a distance of 50 cm from the pivot. This means that the torque created by this load is 50 cm x Fw. In order for the bar to be in equilibrium, there must be an equal and opposite torque acting on the other side of the pivot. This means that the clay must also have a torque of 50 cm x Fw. Since we know that the distance of the clay from the pivot is 55 cm, we can solve for the weight of the clay using the equation torque = force x distance. This gives us 50 cm x Fw = 55 cm x Fc (where Fc is the weight of the clay). Solving for Fc, we get Fc = 1.0 N. Therefore, the answer to the second question is also a. Fw.

To summarize, in order to solve equilibrium problems with a frictionless