All forces come in pairs (in opposite directions)
Two objects that touch..
Every two objects that touch apply a contact force to each other
Beginning of motion
The beginning of motion is always caused by forces
Object’s motion is influenced..
An object’s motion is influence only by the forces that are applied to it,not by the forces it applies to others
Forces that are applied to an object in opposite directions..
Counteract each other
Forces that are applied to an object in the same direction..
Reinforce one another
Combine all forces
If forces act in opposite, equal directions… if forces act in opposite directions then ______ to find net force.
They cancel each other out…subtract
Equal, opposite forces = net force of…
Two forces acting on the same object in the same direction a
Added together to determine net force
Explain why objects begin to move
A force is applied to the objects, setting them in motion
Horizontal and vertical forces
Many cases horizontal causes motion
Move towards one side if the force on the other end is greater
When do two forces that are applied to an object counteract each other?
Forces come in opposite directions, same object
When do two forces that are applied to an object reinforce each other?
come in the same direction, same object
When do two forces that are applied to an object cancel each other?
When they are equally strong, opposite direction, same object
An object applies forces to several other things around it. Do these forces influence the object’s motion?
No, motion is only influenced by the forces applied to it, not by the forces it applies to others
For something to move upwards, it has to overcome what force
Under what conditions do forces counteract each other?
Acting in opposite directions, acting on the same object
Under what conditions do forces reinforce each other?
Acting in the same direction, acting on the same object
Under what conditions do forces cancel each other?
Equal strenght, opposite directions, same object
Grams are used to measure…
Newtons are used to measure…
Does a spring get stretched by the same amount each time the same mass is hung frrom it?
Does a spring return to its original shape each time after the mass hanging from it is removed?
Yes, returned to zero
What is the relation between the amount a spring gets stretched and the size of the mass hanging from it?
Greater spring gets stretched, greater mass
How can you tell the size of the mass hanging from it?
Greater the mass, spring gets stretched more
How to covet mass to wight
Divide by 100
How to convert weight to mass
Multiply by 100
Measure of the amount of matter in an object
Force that acts on an object due to gravity
Don’t forget what??
LABELS – units are important (g for grams or N for newtons)
Two contact forces with regards to their directions and magnitudes
Two forces are equal in magnitude in opposite directions
What general relationship do you think there is between pairs of forces?
For every force, there is an equal and opposite force
Comes in pairs that act in opposite directions, act in the parallel to the contact surface rather than perpendicular