Les 5 — Balanced and unbalanced forces

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

This lesson

• Balanced and unbalanced forces
• A video
• Resultant force

Learning goals

• Recognise balanced and unbalanced forces.
• Name two things balanced forces can do.
• Name two things unbalanced forces can do.
• Calculate resultant force.

§1.2 Balanced and unbalanced

forces

• Balanced forces
• Unbalanced forces
• Resultant force

Balanced and unbalanced

forces

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

0

The forces on an object are 

balanced.

How does this effect its motion when...

• It is stationary?

• it is moving at a constant speed?

Balanced Forces

When an object is...

• standing still –> keeps standing still

• Moving –> travels at a constant speed.

The forces on an object are unbalanced.

How does this effect its motion when...

• it is stationary?

• it is moving at a constant speed?

Unbalanced forces

When an object is...

• standing still –> starts moving

• Moving –> accelerates or decelerates

Resultant force

Homework

Read:'Resultant force' on page 11

Do: the workbook exercises of §1.2

Resultant force?

Resultant force?

Resultant force?

Resultant force?

Learning goals

• Recognise balanced and unbalanced forces.
• Name two things balanced forces can do.
• Name two things unbalanced forces can do.
• Calculate resultant force.