Free Body Diagrams

terminal velocity video Terminal Velocity

The maximum velocity of an object falling

Fair = Fgravity

The force due to air resistance is equal to the force due to gravity Terminal Velocity

The maximum velocity of an object falling

Fair = Fgravity

The force due to air resistance is equal to the force due to gravity

You are still falling, but not accelerating. Draw a free body diagram of a meteor that is falling towards earth at terminal velocity. Draw a free body diagram of a meteor that is falling towards earth at terminal velocity.

Fair

Fgravity Draw a free body diagram of a meteor that is falling towards earth at terminal velocity.

The meteor is falling down, but its net force is 0 N!

Net Force = 0 N Fair

Fgravity There is no acceleration! Free Body Diagrams

Objects do not always move in the same direction as the net force. Free Body Diagrams

Objects do not always move in the same direction as the net force.

Objects accelerate in the same direction of the net force! Free Body Diagrams

Objects do not always move in the same direction as the net force.

Objects accelerate in the same direction of the net force!

What does this mean for deceleration? Free Body Diagrams

When objects slow down (decelerate), they move in the direction OPPOSITE the net force. Free Body Diagrams

When objects slow down (decelerate), they move in the direction OPPOSITE the net force.

Example: A car coasts rightward while slowing down. Free Body Diagrams

When objects slow down (decelerate), they move in the direction OPPOSITE the net force.

Example: A car coasts rightward while slowing down. MOTION Fnormal

Ffriction Since the car is coasting to the right, there is no force being applied to the right.

Fgravity Free Body Diagrams

Practice: worksheet What is weight?

F=ma What is weight?

F=ma

Fgravity = ma

Weight = mass * 9.8 m/s2 Free body diagrams...with numbers? A box is pushed across a table.

Fnormal = 10 N

F = 10 N normal Fapplied = 8 N

Fgravity