Force & Work NotesTEKS 6.8E investigate how inclined planes and pulleys can be used to change the amount of force to move an objectTEKS 7.7A contrast situations where work is done with different amounts of force to situations where no work is done such as moving a box with a ramp and without a ramp, or standing still
A force is anypush or pull on an object.
When a force isexerted thatmoves an objectyou dowork.
The force mustbe in the samedirection as theobject’s motion.
The unit ofmeasurementfor force isNewtons.
The tool used tomeasure weightor force is a spring scale.
The unit ofmeasurement for work is Joules.
Work can becalculated using thefollowing formula: W = F X d Work = Force X distance
How much work is done if a force of 20 Newtons moves a box 4 meters? 20N 4m
20N 4mW = F X dW = 20N X 4mW = 80 Joules
The change inposition of anobject…Motion
Device thatmakes effortseem easier…Machine
Object to bemoved…Load orResistance
Force youexert on amachine…Input force
Force exertedby a machine…Output force
Compares the amount ofoutput force to theamount of force input. Efficiency
3 ways machines canchange force… amount direction distance
Inclined plane:Flat surface that slopes.
Less input forceneeded to move anobject, but itmust be movedover a greaterdistance.
Pulley: Wheel with a rope, cable orchain around it.
Can change thedirection and theamount of the inputforce by increasingthe distance overwhich the force isapplied.