“DO NOW” FOR TUESDAY, FEBRUARY 4TH

WHAT TYPE OF FORCES ARE NECESSARY IN ORDER FOR AN OBJECT TO MOVE? THERE ARE TWO POSSIBLE ANSWERS.

“Do Now” for Thursday!

Draw a balanced and an unbalanced force.Illustrate the net force in each drawing.

Forces = Pushes & Pulls!

We know that the strength of a force is measured in SI units called Newtons…After Sir Isaac Newton. 1

Newton is equal to about 102 grams (0.22481 pounds).

Sir Isaac Newton

Net Force is the sum or difference of the forces on an object.

Net force = 300NGreen Team Wins!

What is a NON-ZERO FORCE?Same as an unbalanced force!

Non-zero = Unbalanced = Movement!

What is a ZERO FORCE?Same as a balanced force!Zero force = Balanced = NO Movement

Balanced?

Balanced?

Balanced?

So what is WORK??

Work is done when an object is moved in the direction in which a force is applied to

it.

Is There Work Without Motion?

NOPE!No Work Here!

Carrying your backpack to school might seem like work - but it’s not!

^^^FORCE

DIRECTION

The force must be in the direction the object moves!!!

Pushing, dragging or pulling your backpack = work!

FORMULA FOR WORK!

Work = Force X Distance(Newtons)

(Meters)

Work is calculated as the amount of force applied to an object times the distance the object moves. The term JOULE is used to describe a unit of work.

(Joule)

FYI – A 500N runner in the Empire State Building’s “Run-Up-Race” creates 160,000 joules of work while climbing the 1,576 steps. Enough

work to lift an elephant over 3 meters!

What is Power?

FORMULA FOR POWER!Power = Work OR Power = Force X Distance Time Time

Power is described in Joules/Second units called WATTS.

One joule of work done in one second = one watt of power.

A watt is a very small unit!Power is often measured in larger units such as Kilowatts (Kw) or Horsepower (hp).

1 Kilowatt = 1,000 watts1 Horsepower = 746 wattsThe average car has 110 – 150 hp.The average semi-truck has 200-400 hpA drag race car can have over 5,000 hpThe average horse has 22.5 hp.

Try some Equations!