This is not the document you are looking for? Use the search form below to find more!

0.00 (0 votes)

TURNING EFFECT OF FORCES MOMENTS Lesson Objectives Identify what are the forces that will give rise to clockwise / anticlockwise moments Calculate clockwise / anticlockwise moments Use the principle of…

- Added:
**May, 12th 2011** - Reads:
**543** - Downloads:
**3** - File size:
**703.02kb** - Pages:
**25** - content preview

- Name:
**lidewei**

Related Documents

The true spinach does not grow well in warm climates and for that reason is not commercialized in Brazil. Instead, a spinach substitute , originally from New Zealand, is widely used ...

The relation between information quality and cost of capital is of significant academic interest and many explanations (e.g., estimation risk, market risk, liquidity) have been posited ...

Like any myth constantly reiterated sounds like truth, myths on the effect of cell tower radiation have been hammered on the common man's mind so often that it is considered as the fact of life. ...

Main subject of this paper is to understand whether there could be an incentive for managers to manipulate cash flow from operating activities (CFO) through the use of real earnings ...

Twelve dairy cows 130 days in milk were sorted by milk production and body weight and assigned to three feeding regimens in a 3 × 3 Latin-square design, in order to study the effects of diet on ...

The number of procedures for registering a business varies from 2 in Canada to 21 in the Dominican Republic. Many have argued, on the basis of cross country evidence, that complex ...

When people get excited about their prospects on the stock market, they borrow money from the bank to invest. This leverage effectively couples the bank to the stock market. Thus, interest

A wide array of antioxidative and anti-inflammatory substances derived from edible plants have been reported to possess chemopreventive and chemoprotective activities. Among the most ...

The present investigation was carried out to study the effect of different concentrations of calcium chloride (1%, 1.5%, 2%), paraffin wax coating and different wrapping materials ...

The study was undertaken to check the effect of freezing conditions of storing strawberries on the level of the thawing drip loss. Research material was divided into three parts, each of ...

Content Preview

- TURNING EFFECT OF FORCES MOMENTS
- Lesson Objectives
- Identify what are the forces that will give rise to clockwise / anticlockwise moments

- Calculate clockwise / anticlockwise moments

- Use the principle of moments to solve problems.

- MOMENTS What is moments? A force can cause many things to move or stop. When a force causes an object to turn, this turning effect is called moments. Example: A person sitting on a see-saw.
- MOMENTS What is moments? A force can cause many things to move or stop. When a force causes an object to turn, this turning effect is called moments. Example: A person sitting on a see-saw.
- Types Of Moments
- There are 2 types of moments:

- Clockwise moment

- Anticlockwise moment

- Types Of Moments
- There are 2 types of moments:

- Clockwise moment

- Anticlockwise moment

- Clockwise Moment When a force causes an object to turn in a clockwise direction, it is called a CLOCKWISE MOMENT . To determine if the force causes a clockwise or anticlockwise moment, we have to ignore all other forces acting on the object. When the girl sits on the see-saw, her weight is the force exerted on the see-saw. weight
- Clockwise Moment When a force causes an object to turn in a clockwise direction, it is called a CLOCKWISE MOMENT . To determine if the force causes a clockwise or anticlockwise moment, we have to ignore all other forces acting on the object. When the girl sits on the see-saw, her weight is the force exerted on the see-saw. weight
- ANTI-Clockwise Moment When a force causes an object to turn in an anti-clockwise direction, it is called a ANTI-CLOCKWISE MOMENT . To determine if the force causes a clockwise or anticlockwise moment, we have to ignore all other forces acting on the object. When the girl sits on the see-saw, her weight is the force exerted on the see-saw. weight
- ANTI-Clockwise Moment When a force causes an object to turn in an anti-clockwise direction, it is called a ANTI-CLOCKWISE MOMENT . To determine if the force causes a clockwise or anticlockwise moment, we have to ignore all other forces acting on the object. When the girl sits on the see-saw, her weight is the force exerted on the see-saw. weight
- CALCULATING MOMENTS Moment = force ? perpendicular distance between force and pivot In symbols: Moments = F ? d Weight => F d Unit for moments: Newton-metre (Nm)
- Example 1: A cat of weight 20N stands on one end of a see-saw and the distance between the cat and the pivot is 3m, find the moment. Solution: In this case the cat is causing a clockwise moment. Clockwise moment = F x d = 20 x 3 = 60 Nm F = 20N d = 3m
- Example 2: A duck stands on one end of a see-saw, 5m away from the pivot. If the weight of the duck is 10N, find the moment. Solution: The duck’s weight is causing an anticlockwise moment. Anticlockwise moment = F x d = 10 x 5 = 50 Nm F = 10N d = 5m
- Examples which is the distance? Where is the force & pivot? F d d F F d d d F F
- weight weight Principle of Moments For an object to be in equilibrium(stable/not moving), the total clockwise moment must be equal to the anticlockwise moment about the same pivot point. pivot It is the fixed(non moving) point
- SOLVING PROBLEMS RELATED TO PRINCIPLE OF MOMENTS Step 1: Identify what are the forces that will give rise to clockwise / anticlockwise moment Step 2: Find the clockwise / anticlockwise moment Step 3: Equate the clockwise and anticlockwise moments
- Find the value of d. WORKED EXAMPLE 10N 30N 6m d
- Step 1: Identify what are the forces that will give rise to clockwise / anticlockwise moment
- Find the value of d. WORKED EXAMPLE Anticlockwise moment Clockwise moment 10N 30N 6m d
- Step 2: Find the clockwise / anticlockwise moment
- Clockwise moment = Force x distance between force and pivot = 30 x d = 30d Nm WORKED EXAMPLE Anticlockwise moment Clockwise moment Anticlockwise moment = Force x distance between force and pivot = 10 x 6 = 60 Nm Find the value of d. Solution: 10N 30N 6m d
- Step 3: Equate the clockwise and anticlockwise moments
- Find the value of d. Solution: Clockwise moment = Force x distance between force and pivot = 30 x d = 30d Nm Anticlockwise moment = Force x distance between force and pivot = 10 x 6 = 60 Nm Using the principle of moments, Clockwise moment = Anti-clockwise moment 30d = 60 d = 60 ? 30 d = 2 m WORKED EXAMPLE Anticlockwise moment Clockwise moment 10N 30N 6m d
- Points to note:
- The unit for force must be in Newtons, the unit for distance must be in metres.

- The distance must measured from the force to the pivot.

## Add New Comment