Forces💥(Lower sec)

Forces 💥 Push and Pull 5.1Whatisaforce? 5.1.1 Intro-It is a push or a pull, which can:~change the state of rest or motion of a body~change the shape and size of a body~bring about turning effects in a body(eg levers)~exert pressure on a body Examples:1. rotating of nut using spanner2. turning doorknob3. Lifting a heavy stone with a lever The S.I unit of force is Newton(N).Eg. force F=2.7N

The magnitude of a force is measured using a forcemeter (or newton metre) eg. spring balance, digitalforce gauge 5.1.2 Weight Vs Mass Mass Weight Definition Amount of substance in abody or object(no. and composition ofatoms and molecules makeup the mass of a body) A body on earth’s surfaceexperiences a downwardgravitational force which isthe pulling force of it due toearth. The force is also calledthe weight of the body S.I Unit Kilogram (kg) Newton (N) Other commonUnits milligram(mg) and gram(g) Instruments usedto measure Electronic balance or beambalance Extension spring balance orcompression spring balance Note:Don'tmixmassandweight‼ Formula of force: W = mgW= weight (N)m= mass (kg)g= gravitational field strength (N/kg) Note: Weight and Force is the same thing ‼→both of them have the SI unit of Newton(N) Types of Forces

GravitationalForce, W(non-contact) Aka weight, it is a gravitational force or forcedue to gravity acting on a body. Friction, F(contact) Occurs when 2 surfaces rub against each other.It can be solids, liquid or gases.(In liquid andgases: commonly called viscous force or dragforce)- In air: called air resistance- Smooth surface has negligible resistance

Tension, T(contact) Normal ContactForce, N(contact) 5.1.3 How To Draw Free Body Diagram

Normal Contact force: touches thebottom of the box, upwards Weight: starts exactly in the middle ofthe box, downwards Push/Pull: from the outside surface ofthe box, in the direction of the force Friction: On top of the surface of thebox touching the floor (to allow thecher to see what u draw),against thedirection of the force