GCSE PHYSICS UNIT 3 NOTES

Lets use the example of a bus, 

When the LINE OF ACTION is beyond the pivot there will be clockwise moment and the bus will topple over.

(SEE EXAMPLE PICTURE ON NEXT CARD)

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The LINE OF ACTION is the straight line that comes down from the centre of mass 

Centripetal force causes acceleration. It's always to the centre of the circle.

CENTRIPETAL FORCE INCREASE IF :

• MASS IS INCREASED

• SPEED IS INCREASED

• RADIUS IS DECREASED

GRAVITY DECREASES WITH DISTANCE

IF YOU DOUBLE THE DISTANCE, THE FORCE OF GRAVITY DECREASES BY 4 TIMES.

THIS IS CALLED AN INVERSE SQUARE LAW

Orbits tend to be a slightly squashed circle called and ELLIPSE