Download - Force
RELATIONSHIP BETWEEN FORCEAND PRESSURE
FRICTION
EFFECTS OF FORCE
INTRODUCTION
FORCE
- playing a guitar - scrubbing the floor - sawing wood - rowing a boat
• A pull is when we apply a force to move an object towards our body
• A force to move an object away from our bodies
FORCE
A force is a push or a pull or both. A force cannot be seen but we can feel andobserve the effects of the force.
PUSH PULL
COMBINATION OF PUSH AND PULL
Stops a moving object or makes astationary object
moves
Change thespeed of a
moving object
Change thedirection of amoving object
Changes theshape
permanently
Changes theshape
temporarily
EFFECTS OFA FORCE
Stretch a rubber bandStretch a rubber band
After
An object that will return to its original shape and size after being squeezed, pressed, twisted and stretched is elastic
After After
Press a spongePress a sponge Squeeze a springSqueeze a spring
Drop a glassDrop a glass
After After
Tear a piece of paperTear a piece of paper
After
Crush an empty canCrush an empty can
An object that will not return to its original shape and size after being squeezed,pressed, twisted and stretched is inelastic
A solid cannot be compressed or stretched!!
IMPORTANT POINTIMPORTANT POINT
EXPLANATIONEXPLANATION
The shape of a solid object changes when a force is applied to it whether it’s temporarily or permanentlyExample: crushing a can – changes the shape permanently
when a force is applied in the opposite direction (or different direction), the moving object will change its moving direction
Misconception?A force is needed to keep an object moving with a constant speed
Explanation:You do not need forces to move at a steady speed but if you keep the same speed yet change direction, like a moon around a planet, then you have a force acting on you anyway
An object will move faster when a force is appliedIt moves in the same direction as the applied force
• A stationary ball will move when it is kicked • Moves in the same direction as the applied force
•The moving ball will stop when an equal force is applied in the opposite direction of its motion
Force is a property of an object. An object has force and when it runs out of force it stops moving
EXPLANATIONEXPLANATION
an object at rest or in motion will remain in that state unless an external force is applied to the object
Newton 1st Law