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Big question How many weights can I place on the ruler before it tips?
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By the end of this topic you should:
Objectives
Levers
Big question
• How many weights can I place on the ruler before it tips?
Hydraulics
05/04/23 6
Pressure = Force Area
• Weight measured in Newton's N
• Area measured in meters squared M2
• Pressure measured Newton meters squared
N/ M2 or NM - 2
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If you push down one side 5 M the other will move?
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Centre of gravity
Center of gravity can be out side the object
• http://www.youtube.com/watch?v=QQh56geU0X8
Pendulum key words
• Amplitude (how far from vertical the string moves)
• Period ( time taken for one swing)• Frequency ( number of swings per secon)
Which falls faster heavy or light?
• http://www.bing.com/videos/search?q=happer+feather&view=detail&mid=4B4A1DFA822F65022B7B4B4A1DFA822F65022B7B&first=0&FORM=NVPFVR
Cirular motion
• http://www.bing.com/videos/search?q=wall+of+death+fair+ground&view=detail&mid=0A8553C1DD64230FA31E0A8553C1DD64230FA31E&first=0&FORM=NVPFVR
Centripetal force
• Is any force that acts at 90 degrees to objects motion (towards centre of circle) of object.
• With out which object flies off in straight line
Magnetic feilds
The earth acts as a magnet
The earth acts as a magnet
• Arrows on field are drawn north to south
• Where the lines are close together the field is strongest
• In electromagnets field can change direction by changing the current
• http://www.bing.com/videos/search?q=faraday+electric+motor&view=detail&mid=2F7A37DE404A15A0777A2F7A37DE404A15A0777A&first=0&FORM=NVPFVR
Make a stronger motor
• More coils of wire• More current• Stronger magnet
• (changing direction of current changes direction of spin)
• http://www.bing.com/videos/search?q=electric+motor&view=detail&mid=C357EF84B0840FC41766C357EF84B0840FC41766&first=0&FORM=NVPFVR
Practical problems
Step up transformer
• Always with respect to voltage
Less coils more coils
Step down transformer
• Always with respect to voltage
Less coils more coils
Stepping up
• 12 22
Stepping up
• 1:2 ratio voltage times 2
• 1:2 ratio voltage times 2• 1:3 ratio voltage times 3• 1:4 ratio voltage times 4• 1:5ratio voltage times 5
• Ratio = big number / small one
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