Newton’s First Law

Do bombs drop straight down from an airplane?

Objects in motion

Stay in Motion

Objects at rest

Stay at rest

“An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force."

Is there an

unbalanced force at work here?

Stay in Motion

Inertia

Why seat belts were invented

A ball is launched straight up from a moving truck. Ignoring air resistance, where does the ball land relative to the truck?

The forward inertia of the ball is unaffected by its upward

motion.

Newton’s Second Law of Motion

Fnet=maF= force

m = mass

a= acceleration

Fnet=maFnet= force

m = mass

a= acceleration

Fnet=maFnet= force

m = mass

a= acceleration

Fnet=maFnet= force

m = mass

a= acceleration

Fnet=maFnet= force

m = mass

a= acceleration

What is net force?

Object accelerates

LARGER Force moving object forward

Smaller force resisting forward movement

What is net force?

Object maintains constant velocity

Force moving object forward

Equal force resisting motion

Newton’s Third law of Motion

Which team is applying more force to the

rope?

Neither- Both teams apply equal and opposite force.

•For every action force, there is a reaction force equal in strength and opposite in direction.

•For every action force, there is a reaction force equal in strength and opposite in direction.

Coanda effect

Coanda effect

The tendency of fluids to attach to a surface and follow it.

Do the forces on the ball tend to be balanced or unbalanced?

• Air moving along wing

• Deflected downwards when leaving wing

• Pushes craft up into the air

• Newton’s 3rd Law