# Moments - How are they actually calculated?

• 012anonymousx

#### 012anonymousx

Moments -- How are they actually calculated?

Hello, I have a question.

Is the moment calculated:

Force times the distance or

Force's perpendicular component (to axis) times the distance.

For example, let's say I have a stick.

Pulling on it is not moment.

So if I push at the stick to an angle, the way I calculate the force that the other side is applying is by taking the perpendicular component of my Fa and multiplying it by the distance.

Is that correct?

Yes, when you are calculating moments, you would use the perpendicular component. The parallel component will not produce any moment as the perpendicular distance is zero.

• 1 person
Mathematically, a moment is ##\vec{l} = \vec{r} \times \vec{f}##. The magnitude comes out as ##l = rf\sin\theta##, where ##\theta## is the angle between the position vector and the force vector. This is equivalent to saying that it is the perpendicular component of the force.

• 1 person
Thank you!

## 1. How do you define a moment in physics?

A moment in physics is a measure of the turning effect of a force. It is calculated by multiplying the magnitude of the force by the perpendicular distance from the pivot point to the line of action of the force.

## 2. What is the equation for calculating a moment?

The equation for calculating a moment is M = F x d, where M is the moment, F is the force applied, and d is the perpendicular distance from the pivot point to the line of action of the force.

## 3. How are moments calculated in real-world applications?

In real-world applications, moments can be calculated by using tools such as rulers, protractors, and force meters. These tools help to accurately measure the force and distance components needed for the calculation.

## 4. Can moments be negative?

Yes, moments can be negative. A negative moment indicates that the turning effect of the force is in the opposite direction compared to a positive moment. This can happen when the force is applied in the opposite direction of the rotation or if the pivot point is on the opposite side of the line of action of the force.

## 5. How do moments affect the stability of an object?

Moments play a crucial role in determining the stability of an object. If the total clockwise moments are equal to the total anticlockwise moments, the object will be in equilibrium and remain stable. However, if the moments are unbalanced, the object will start to rotate and become unstable.