The Turning Effect of Forces
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The Turning Effect of Forces You should be able to: •state what the centre of gravity of an object is. •describe a simple experiment to determine the centre of gravity of an object. •define and apply the moment of force. •apply the principle of moments to solve problems, including the human forearm.
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The Turning Effect of Forces. You should be able to: state what the centre of gravity of an object is. describe a simple experiment to determine the centre of gravity of an object. define and apply the moment of force. - PowerPoint PPT Presentation
Transcript of The Turning Effect of Forces
The Turning Effect of ForcesYou should be able to:•state what the centre of gravity of an object is.•describe a simple experiment to determine the centre of gravity of an object.•define and apply the moment of force.•apply the principle of moments to solve problems, including the human forearm.
The Turning Effect of Forces
1. Suspend object from a point 2. Use plumb line to find the vertical line and mark it on with a pencil3. Hang from another point and draw another vertical line4. Where the lines intersect gives position of centre of gravity 5. Check your centre of gravity by choosing another point and repeating.
Describe an experiment to find the centre of gravity of an object.
The Turning Effect of Forces
Centre of Gravity – the point where the weight of an object can be considered to act.
The Turning Effect of ForcesCentre of Gravity
The Turning Effect of ForcesDefine and apply the moment of force
The Turning Effect of ForcesDefine and apply the moment of force
The Turning Effect of ForcesDefine and apply the moment of force
The Turning Effect of ForcesDefine and apply the moment of force
The Turning Effect of ForcesDefine and apply the moment of force
Use the equipment available to find ;1)The mass of the rule2)The mass of the unknown weight
The Turning Effect of ForcesDefine and apply the moment of force
The Turning Effect of ForcesDefine and apply the moment of force
The Turning Effect of ForcesDefine and apply the moment of force
The Turning Effect of ForcesYou should be able to:•define and apply the torque of a couple•explain that both the net force and net moment on an object in equilibrium is zero•apply the principle of moments to solveproblems where the perpendicular force has to be calculated.
Couple
The Turning Effect of Forces
The Turning Effect of Forces
What is the significance of this diagram ?
The Turning Effect of Forces
60o
70 kg
W
5 m
3 m
What is the counterweight (W) required to balance the light crane arm shown in diagram ?
The Turning Effect of ForcesWhat is the tension (T) in the cable shown in diagram ?
20 N
3 m
1.5 m
T
70o
The Turning Effect of Forces
T
25 m
20 m
65o
70 N
What is the tension (T) in the cable shown in diagram?
Typical loading diagram
