Les 4

• Natuurkunde / Scheikunde
• Middelbare school
• havo, vwo
• Leerjaar 1

Todays lesson

• Types of forces
• Balanced and unbalance forces
• A video
• Working on §1.2

Learning goals

• Give an example for each type of force.
• Calculating resultant force?
• What two things can balanced forces do?
• What two things can unbalanced forces do?

The homework

Force	Change in speed	Chang in direction
Gravity acting on an apple
Friction acting on a car going a round a corner at a steady speed
Friction when a car brakes in a straight line

Types of Forces

Gravitational force

Friction

Thrust

Upthrust

Tension

Electrostatic force

Magnetic force

Thrust

The force applied by an engine

Thrust

The force of an engine

We now finished § 1.1

§1.2 Balanced and unbalanced forces

• Balanced forces
• Unbalanced forces
• Resultant force

Resultant forces?

Resultant force?

Resultant force?

Calculating the resultant force

Forces in the same direction add up.

Forces in opposite direction cancel out.

Video — Exercise

• Acceleration
• Deceleration
• Constant velocity
• Stationary
• Weight
• equal

What do the words below mean?

Discuss in pairs and write down your answer

Acceleration	Speeding up
Decceleration	Slowing down
Constant velocity	Traveling at one speed
Stationary	Standing still
Weight	The force that pulls you to the earth
Equal	Two things being the same

Homework

The Workbook exercises of §1.2

Learning goals

• Give an example for each type of force.
• Calculating resultant force?
• What two things can balanced forces do?
• What two things can unbalanced forces do?

Balanced and unbalance forces

Balanced forces

• Object remains stationary
• Object keeps moving at a constant velocity

Unbalanced Forces

• Accelerate
• Decelerate

Homework

The Workbook exercises of §1.2