# 1-1 Introduction and forces

Introduction and forces
(p. 8)

Stationary
- Book and writingbook
- Pen, pencil
- Calculator
REPORT
- NO

Lessonup
- YES
Schoolbag in
the cupboard
Phones in the phonebag
1 / 16
Slide 1: Slide
NatuurkundeMiddelbare schoolvwoLeerjaar 3

This lesson contains 16 slides, with interactive quizzes and text slides.

Lesson duration is: 50 min

## Items in this lesson

Introduction and forces
(p. 8)

Stationary
- Book and writingbook
- Pen, pencil
- Calculator
REPORT
- NO

Lessonup
- YES
Schoolbag in
the cupboard
Phones in the phonebag

#### Slide 1 -Slide

Forces can do three things:
• Change the speed of an object
• Change the direction of an object
• Change the
shape of an
object

#### Slide 2 -Slide

Types of forces:
• Muscular strength
• Resistance or resilience
• Tention (rope)

• Gravity
• Magnetic force
• Friction
or
Forces are measured with a dynamometer in Newton.
Fmusc
Fr
FT
Fgr
Ff
f

#### Slide 3 -Slide

Calculating gravitational force:
To calculate the gravitational force on an object we use the formula...
F = mg
where g = 9.8 N/kg

#### Slide 4 -Slide

Calculating gravity
If you have the mass of an object in kg,
then you can calculate the force of gravity with:
mass x 9.8
Fgr

#### Slide 5 -Slide

Example 1
What is the gravitational force of an object with a mass of
550 grams?

#### Slide 6 -Slide

Example 2
If the gravity on an object is 900 N, what then is the mass of the object?

#### Slide 7 -Slide

Which of the following is NOT an effect of forces:
A
Increase speed
B
Change direction
C
Change shape
D
Attract an object

#### Slide 8 -Quiz

Which of the following is NOT a type of force?
A
Muscular strength
B
Mass force
C
Magnetic force
D
Resilience

#### Slide 9 -Quiz

What can be used to measure forces?
A
Ruler
B
Dynamometer
C
Newton scale
D
An estimation

#### Slide 10 -Quiz

What must be the unit of mass if you want to calculate force?
A
ton
B
kg
C
g
D
mg

#### Slide 11 -Quiz

When do you divide with 9,8 and when do you multiply with 9,8?

#### Slide 12 -Open question

What is the gravitational force on a tennis ball with a mass of 56 grams?
A
548,8 N
B
5,7 N
C
0,549N
D
0,57N

#### Slide 13 -Quiz

What is the mass of an antelope with a gravitational force of 2 499 N?
A
255 kg
B
2,55 kg
C
24 490 kg
D
24,49 kg

What did you
learn today?

#### Slide 15 -Mind map

Conclusion:
• Forces can change the speed, direcition
and shape of an object.
• With elastic deformation the object returns to its original shape and with plastic deformation the deformation is permanent.
• Types of forces: Muscular strength, resilience, gravitational force and magnetic force.

F=ma