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De Lisle Catholic Science College Science department Key stage 3. Year 9 Moments & Levers J.Maden. Moments & Levers explorer. Click here to see all of the presentation. Click here to go directly to moment equation. Click here to go directly to moment problems. Click here to go
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De Lisle Catholic Science CollegeScience departmentKey stage 3 Year 9 Moments & Levers J.Maden
Moments & Levers explorer Click here to see all of the presentation Click here to go directly to moment equation Click here to go directly to moment problems Click here to go directly to levers
Introduction to Moments • What is a moment? • a moment is a turning force • sometimes called a torque • What variables determine the value of a moment? • force • distance force acts from the pivot • What is the unit of moments? • the unit of a moment is the newton metre (Nm)
Moment equation Moment (M) X Distance (d) Force (F) Nm N m Moment = Force X Distance Nm = N X m
Beam balancing Pivot
Law of moments • What is the law of moments (or balancing)? clockwise moments = anticlockwise moments F1 x d1 = F2 x d2
Moments problem 1 0.1m F • Calculate the moment exerted on the nut when a force of 100N is applied • b) Calculate the force needed to exert a moment of 50Nm?
Moments problem 2 2m Agnes 300N Margaret 600N • How far from the pivot must Margaret stand to balance the see-saw?
Moments problem 3 2m ? 5m • How far from the pivot is the 6N box if the beam is balanced? 6N box 4N box 2N box
Moments problem table 3 2 9 18 3 3
Levers • What can levers do? • either multiply a force (reduce the effort force needed to do work) • or multiply a distance (reduce the distance that an effort force needs to be exerted over) • What can levers not do? • reduce the work needed to do a job • because of friction at the pivot, more work is done using a lever
Lever as a force multiplier Effort force small Pivot Load force large
Lever as a distance multiplier Pivot Load force small Effort force large
Types of lever – class 1 pivot between the load and effort Effort force Pivot Load force
Types of lever – class 2 Effort force Pivot Load force load between the pivot and effort
Types of lever – class 3 Effort force Load force Pivot effort between the pivot and load
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