# Turning effect of force (Moments)

• xiaomeizi
In summary: In addition to the weight force, there is a radial force in the meter stick from the centripetal acceleration. The scale reading varies from a minimum at the start to a maximum at the bottom of the circle.In summary, a previous post was combined by a mentor with the original post on the same topic. The question asked is whether the reading on the spring balance will be the same or vary when the spring balance is moved rightwards, causing the meter ruler to rotate due to the turning effect of the force. The reading will vary because the meter stick is no longer in equilibrium and is accelerating both vertically and horizontally. The radial
xiaomeizi
My previous post has been removed due to some reasons.
I would like to ask another question: if a uniform metre ruler with weight of 1.2N, suspended at its mid-point from a spring balance. No other force is added to the ruler.
The reading on the spring balance is 1.2N. Am I right?

If the spring balance is move rightwards, which causes the ruler to rotate due to turning effect, will the reading on the spring balance be the same or will it vary because of the turning effect of the force.

xiaomeizi said:
My previous post has been removed due to some reasons.
it wasn't removed, it was combined by a mentor with your original post on the same topic.
I would like to ask another question: if a uniform metre ruler with weight of 1.2N, suspended at its mid-point from a spring balance. No other force is added to the ruler.
The reading on the spring balance is 1.2N. Am I right?
Yes, indeed.
If the spring balance is move rightwards, which causes the ruler to rotate due to turning effect, will the reading on the spring balance be the same or will it vary because of the turning effect of the force.
It will vary since it is no longer in equilibrium, since the center of mass of the meter stick is now accelerating vertically and horizontally (or tangentially and radially).

PhanthomJay said:
it wasn't removed, it was combined by a mentor with your original post on the same topic.Yes, indeed.
It will vary since it is no longer in equilibrium, since the center of mass of the meter stick is now accelerating vertically and horizontally (or tangentially and radially).

thanks for your reply. ' It will vary since it is no longer in equilibrium'.. But I don't really get it. i thought the only force acting downwards is the weight of the meter stick. So if the reading on the spring balance varies, is it larger than 1.2N or smaller?

xiaomeizi said:
thanks for your reply. ' It will vary since it is no longer in equilibrium'.. But I don't really get it. i thought the only force acting downwards is the weight of the meter stick. So if the reading on the spring balance varies, is it larger than 1.2N or smaller?
Don't forget that the stick is rotating and it is accelerating in both the tangential and radial directions. In addition to the weight force, there is a radial force in the meter stick from the centripetal acceleration. The scale reading varies from a minimum at the start to a maximum at the bottom of the circle.

PhanthomJay said:
Don't forget that the stick is rotating and it is accelerating in both the tangential and radial directions. In addition to the weight force, there is a radial force in the meter stick from the centripetal acceleration. The scale reading varies from a minimum at the start to a maximum at the bottom of the circle.

I think I have understood it with your clear explanation.
I am really grateful for your help.

## What is the turning effect of force?

The turning effect of force, also known as moments, is a physical concept that describes the tendency of a force to rotate an object about an axis. It is dependent on the magnitude and direction of the force, as well as the distance between the force and the axis of rotation.

## How is the turning effect of force calculated?

The turning effect of force, or moment, is calculated by multiplying the force by the perpendicular distance from the force to the axis of rotation. Mathematically, it is represented as M = F x d, where M is the moment, F is the force, and d is the distance.

## What is the principle of moments?

The principle of moments states that for an object to be in equilibrium, the sum of the clockwise moments must be equal to the sum of the anticlockwise moments. This principle is used to solve problems involving moments and determine unknown forces or distances.

## What are the units of measurement for moments?

The SI unit for moments is newton-meter (Nm). However, moments can also be measured in other units such as foot-pounds (ft-lb) or inch-pounds (in-lb). It is important to use consistent units when calculating moments to avoid errors.

## How is the turning effect of force applied in real-life situations?

The turning effect of force is applied in many real-life situations, such as opening a door, turning a steering wheel, or using a wrench to tighten a bolt. It is also important in engineering and construction, as it is used to design and build structures that can withstand forces and moments. Understanding moments is crucial in fields such as mechanics, physics, and architecture.

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