REVATHY R NATHAN

WELCOMEPhysical Science

SABARIGIRI COLLEGE OF EDUCATION

FORCE AND PRESSURE

FORCE

INTRODUCTION

EFFECTS OF FORCE

FRICTION

RELATIONSHIP BETWEEN FORCE AND PRESSURE

FORCE IS A PUSH OR PULL OR BOTH

A force to move an object away from our bodies

A pull is when we apply a force to move an object

towards our body

PUSH PULL

Launching Rocket Pulling

a box

COMBINATION OF PUSH AND PULL

Playing a guitar

Sawing wood Scrubbing the floor

Rowing a boat

EFECT OF

FORCE

CHANGES THE SHAPE TEMPORARILYCHANGES THE SHAPE PERMANENTLYCHANGES THE DIRECTION OF A MOVING OBJECTCHANGES THE SPEED OF A MOVING OBJECTSTOPS A MOVING OBJECT OR MAKES A STATIONARY OBJECT MOVES

CHILDREN’S MISCONCEPTION

A SOLID CANNOT BE COMPRESSED OR STRETCHED

EXPLANATION

THE SHAPE OF A SOLID OBJECT CHANGES WHEN A FORCE IS APPLIED TO IT WHETHER IT’S TEMPORARIRLY OR

PERMANENTLY EXAMPLE : CRUSHING A CAN

(CHANGES THE SHAPE PERMANENTLY)

WHEN A FORCE IS APPLIED

IN AN OPPOSITE

DIRECTION (DIFFERENT

DIRECTION) THE APPLYING

OBJECT WILL CHANGE

THE MOVING DIRECTION

A STATIONARY BALL WILL MOVE WHEN IT IS KICKED

THE MOVING BALL WILL STOP WHEN AN EQUAL FORCE IS APPLIED IN THE OPPOSITE DIRECTION OF ITS MOTION

MOVES IN THE SAME DIRECTION AS IS THE APPLIED FORCE

FORCE IS A PROPERTY OF AN OBJECT. AN OBJECT HAS FORCE WHEN IT RUNS OUT OF FORCE IT STOPS MOVING

EXPLANATION

AN OBJECT AT REST OR IN MOTION WILL

REMAIN IN THAT STATE UNLESS AN EXTERNAL FORCE IS APPLIED TO

THE OBJECT

NEWTON 1ST LAW

FRICTIONOCCURES WHEN TWO SURFACES ARE MOVING

IN CONTACT WITH EACH OTHER

FACTORS THAT EFFECT FRICTION:

Physical condition of the surface Weight of an object

WAYS TO REDUCE:

Use ball bearing Use wheel and axle

FRICTIONADVANTAGES: Enables people to run and work without falling or slipping

Enables us to write on paper

Enables a car to stop when the brakes are applied

DISADVANTAGES:

Slow down a moving object

Causes the surfaces of objects to wear out Causes less effectiveness of moving machine

EXAMPLES OF FRICTION

RELATIONSHIP BETWEEN FORCE AND PRESSURE

AIR PRESSURE

PULL AND PUSH

APPLYING FORCE

A FORCE IS APPLIED TO THE PUMP TO PRODUCE AIR PRESSURE

THANKS