Mastering Equilibrium: Vectors, Torques, and Balancing - Pre-Lab Questions

  • Thread starter Thread starter slydg895
  • Start date Start date
AI Thread Summary
The discussion revolves around pre-lab questions related to equilibrium, vectors, and torques. Participants evaluate answers to questions about conditions for equilibrium, the definition of torque, and calculations involving lever arms and net torque. There is a consensus that the condition ∑ Fi = 0 alone does not guarantee equilibrium, and the right-hand rule is used to determine the signs of torques. Some answers, particularly regarding the placement of masses for balance, are questioned for accuracy, emphasizing the need to consider the relationship between mass and distance from the pivot. Overall, the conversation aims to clarify concepts and validate calculations before the lab session.
slydg895
Messages
6
Reaction score
0

Homework Statement


1.
The condition ∑ Fi = 0 is not sufficient to assure that a rigid body is in equilibrium.

TrueFalse


2.A quantity that expresses how a force can create an angular acceleration is called

a. moment of inertia
b. angular influence
c. angular energy
d. angular momentum
e. torque

3.
According to the lab manual, clockwise torques are taken as Fill in the Blank 01 (positive or negative) and counterclockwise torques are taken as Fill in the Blank 02 (positive or negative).


4.
Calculate the lever arm of F as measured from the point O. The angle is θ = 42o and the distance r = 1.5 m. Express the answer in meters.

Lever Arm.bmp
Answer
Save Answer

5.Given the situation in the figure below. The mass m1 is 0.55 kg and it is located at x1 = 30 cm. The pivot point is represented by the solid triangle located at x = 45 cm. The mass of the meter stick (mms = 0.40 kg) is located at its geometric center, xms = 50 cm. The mass m2 is 0.35 kg and it is located at x2 = 80 cm. Calculate the net torque (in N⋅m with the proper sign) due to these three weights. Use g = 9.8 m/s2.

Torque Figure.bmp


6. The apparatus described in Question 5 is in equilibrium.

TrueFalse


7.Suppose that a meter stick is balanced at its center. A 0.17-kg is positioned at 31 cm from the left end of the meter stick. Where should a 0.26 kg mass be placed to balance the 0.17 kg mass? Express your answer in terms of the position (in cm) of the 0.26-kg mass as measured from the left end of the meter stick.

BalancedStick.bmp

Homework Equations


Hey guys my proffesor gave us some questions he reccomended to attempt doing before tommorow's lab. I have finished them but we do not have answers so i was wondering if you guys could tell me if i was doing anything wrong.


The Attempt at a Solution


Here are my answers:
1.False
2.Angular momemtum
3.positive(counterclockwise) and negative (clockwise) used right hand rule
4. I got -.599 by using rcos(theta) --i really don't know how to do this one
5.-.098 using T=Fr
6.False
7.63cm
Any help appreciated thanks a lot guys!
 
Last edited by a moderator:
Physics news on Phys.org
1. Why?
2. Don't think that's right
 
1. Beacuse don't the sum of the torques have to be zero?
2. Oh its torque isn't it?
are the others ok?
 
slydg895 said:
1. Beacuse don't the sum of the torques have to be zero?

You have the right answer to my "Why?" question. Do you have the right answer to their question? Watch out for negatives like "not" and "never" in questions...


slydg895 said:
are the others ok?

The only other one I checked was #7, and at first glance it doesn't look right. Aren't they asking where to place a larger mass to balance out the first one? If the 2nd mass is larger, and you want the sum of the torques to be zero, do you place the heavier mass farther out or closer in?
 
Does anyone else know if my other answers are correct?
 
Thread 'Struggling to make relation between elastic force and height'
Hello guys this is what I tried so far. I used the UTS to calculate the force it needs when the rope tears. My idea was to make a relationship/ function that would give me the force depending on height. Yeah i couldnt find a way to solve it. I also thought about how I could use hooks law (how it was given to me in my script) with the thought of instead of having two part of a rope id have one singular rope from the middle to the top where I could find the difference in height. But the...
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Back
Top