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This is an Marathi PPT on gears and Pulleys as a simple machine
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Vigyan Ashram, Pabal
Quick RevisionWeight (N) = mass (kg)
x gravity (m/s2)
pivot
1 m 2 m
? kg 60 kg
•Big distance
•Small force
•Small distance
•Big force
30 kg
Moment (Nm) = Force (N) x distance from pivot (m)
PulleysWhere are pulleys used?Transport over difficult terrain
How do pulleys work?Problem:
We want to lift a 20 kg bucket of water.
Bucket Lift
Too Heavy!
Weight (N) = mass (kg) x gravity (m/s2)
Bucket weight = 20kg x 10m/s2
= 200 N
Weight = 200N
Force to lift bucket = 200N
How do pulleys work?Simple Pulley:
200N
200N
Force In – person pulls rope
Force Out – force to lift bucket upwards
Force In Rope – force is constant along length
Force In = Force Out
Pulley video 1
How do pulleys work?Simple Pulley:
200N
100N
Force In – person pulls rope
Force Out – force to lift bucket upwards
Force In Rope – force is constant along length at 100N
Force Out is more than Force In! •Pulley video 2
Total force to lift bucket upwards
200N
Weight of bucket
Force in each end of rope needed to lift bucket
100N 100N
100N
Mechanical Advantage = ÷
200N200N
Force In – person pulls rope
Force Out – force to lift bucket upwards
Force InMechanical Advantage Force Out
= ÷ 200 N1 200 N
Mechanical Advantage = ÷
200N
100N
Force In – person pulls rope
Force Out – force to lift bucket upwards
Force InMechanical Advantage Force Out
= ÷ 100 N2 200 N
Shortcut! = x Number of movable
pulleysMechanical Advantage 2
200N
50N
Force In – force in rope
Weight
Static Pulleys
Movable Pulleys
= x 24 2
Mechanical Advantage = ÷
200N
50N
Force In – force in rope
Force Out – force to lift bucket upwards
Force InMechanical Advantage Force Out
= ÷ 50 N4 200 N
•4 ropes
•Force In Rope = 200 ÷ 4
Weight
Total Force to lift bucket upwards
50N50N50N50N200N
= x
= x
Shortcut!Force InForce Out Mechanical Advantage
200N
50N
Force In – pull on rope
Force Out – force to lift bucket
Static Pulleys
2 Movable Pulleys
50N200N 4
एक खे�ळ खे�ळ�या!मी� एक कर क पनी�चा मीलक आहे�मील चा�रपसू�नी सू रक्षण हे�ण्यासूठी� एक मी�ठी गे�ट बनीवावा
लगेणर आहे�गे�ट १०००KG चा� आहे� त्यामी"ळ� ते� बहे�रूनी उघडते या�णर नीहे�.मील मीझे� कमीगेर ते� आते�नी उघड� शकते�ल असू कहे�तेर�
करयाचा आहे�मी� हे� कमी स्वास्तेते करू इच्छि/ते�Extra points for creativity and good
presentation! लक्षते ठी� वा ते"म्हे�हे� एक स्पर्ध3क आहेते!
Business Game!
Mechanical Advantage = Force Out (N) ÷ Force In (N)
Cost per item Mass per item
Pulley 1000 rupees 10 kg
Multi-Pulley
2000 rupees 20 kg
Cost per metre
Rope 50 rupees
Cost of electric winch Pulling force of winch
Winch 6000 rupees 2000 N
Mass of Door
Door 1000 kg
वाजनी (N) = वास्ते"मीनी (kg) x गे"रुत्वाकर्ष3
Mechanical Advantage = 2 x number of movable pulleys
Business Game!
कहे� कल्पनी!
निनीयामी4 व्यक्तीं<चा एक सू घteam leader ठीरवा10 mins कल्पनी�निवार्षया� चाचा3 कर20 mins loadचा गेणिणते कर30 mins design work – दरवाज्याचा� रचानी, प"ल@चा� रचानी,
ते"मीच्या रचानी�ते जगे�चा नी�ट वापर हे�ते�या? 20 mins working on business pitch –मी� ते"मीचा� रचानी क
निनीवाड�? ते� नी�ट कमी कर�ल क(गेणिणते पडतेळ�नी पहे), ते"मीचा� रचानी चा गेल@ क आहे�, व्यवासूया कसू .करल?
ल�डच्या गेणिणतेसू गे"ण असूते�ल पण ते� या�ग्या असूवा�ते, नीनिवान्या, कल्पक व्यवासूयियाकते�चा निवाचार, उत्तमी मी डण�.
जिंजHकणऱ्या सू घल आकर्ष3क बक्ष�सू!!!
Promptsकमी�ते किंकHमीते ठी� वा – more pulleys or more
winches?Force श�र्ध Mechanical Advantage श�र्धPulleys निकते� लगेते�ल?किंकHमीते अज�नी कमी� कश� करते या�ईल? Ideas!!!दरवाज आणिण त्याचा� सू रचानी कश� असूयाल हेवा� आणिण त्याचा
वापर कसू करते या�ईल?ते"मीच्याचा व्यवासूयाचा आरखेड मी� क निनीवाडवा?