Force-c.1300, from O.Fr. force, from L.L. fortia, from neut. pl. of L. fortis "strong"

Physics usage: an amount of push or pull in a direction

Contact forces

Non-contact forces

Contact forces

-push or pull due to physical contact between two objects

Write a non-sports example of contact force.

Non-contact forces

-push or pull occurring even though there is no physical contact

Types of forces:

Gravitational :Non-contact force that pushes objects downward

Types of forces:

Normal:

Contact force that a surface exerts on an object with which it is in contact (perpendicular)

Types of forces:

Friction:

Contact force that a surface exerts on an object with which it is in contact (parallel)

Smooth surface=

less friction

Rough surface=

more friction

Types of forces:

Push/pull:

force that opposes friction push/pull

friction

Identify the force for the pictures. Why?

How we calculate force:

F= m x a *units= Newtons (N)

F=force

m=mass

a=acceleration

Calculate the force for the following

1.An object of mass 3 kg accelerating at 5 m/s2.

2.A ball of 2 kg thrown at an acceleration of 56 m/s2.

3.A sumo wrestler of 30kg being thrown at 4 m/s2.

If the applied forces are….. …then the net force is.

20 N

10 N

30 N

10 N 25 N15 N

Movement=unbalanced force (force is not zero)

10 N 10 N

No movement= balanced force (force is zero)

Balanced or unbalanced? Why?

Use the current vocabulary to summarize your learning of forces.