# Y2_T4_LSN_4.3

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ScienceMiddelbare schoolhavo, vwoLeerjaar 2

In deze les zitten 25 slides, met interactieve quizzen en tekstslides.

## Onderdelen in deze les

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#### Slide 1 -Tekstslide

Topic 4
Moving in the world

#### Slide 2 -Tekstslide

Plan for today
• Explanation T4.3 Acceleration
• Make homework

4.3 Acceleration

#### Slide 4 -Tekstslide

Learning goals
I can....
• describe the concept of acceleration and understand which measurements and units are necessary to calculate it.
• calculate the acceleration of an object using the acceleration formula.
• create and interpret v,t-diagrams relating to an object’s change in motion.
• use an object’s resultant force to determine what type of motion it has.

Key words
• Acceleration
• Deceleration
• v,t-diagram

#### Slide 6 -Tekstslide

Acceleration
Acceleration is change in speed, so speeding up or slowing down, measured in meters per second squared
m/s2

#### Slide 7 -Tekstslide

Deceleration
Acceleration is an increase in speed
a is a positive number.

A decrease in speed is called decelaration
a is a negative number

#### Slide 8 -Tekstslide

Acceleration example
Acceleration is positive when speed increases

If the speed increases by 20 m/s in 5 seconds

delta v = v(final) - v(initial)
delta v = 20 - 0 = 20 m/s (so it is positive)

a = 20/5 = 4               (also positive)
m/s2

#### Slide 9 -Tekstslide

Deceleration example
Acceleration is negative (= deceleration) when speed decreases

If the speed decreases by 20 m/s in 5 seconds

delta v = v(final) - v(initial)
delta v = 0 - 20 = -20 m/s (so it is negative)

a = -20/5 =  -4               (also negative)
m/s2

#### Slide 10 -Tekstslide

Petra is at a traffic light. As soon as it hits green, she starts to speed up on her bike. She accelerates with 5
What is her speed after 4 seconds?

m/s2
A
9 m/s
B
1 m/s
C
20 m/s
D
1,25 m/s

#### Slide 11 -Quizvraag

A car is accelerating for 8 seconds, increasing by 20 m/s every second. What is his final speed?
A
28 m/s
B
160 m/s
C
2,5 m/s
D
12 m/s

#### Slide 12 -Quizvraag

convert 18 m/s to km/h
A
14,4 km/h
B
65 km/h
C
5 km/h
D
21,6 km/h

#### Slide 13 -Quizvraag

v,t-diagram
An v,t -Diagram is a graph that shows the speed of an object.

it shows the speed (v) and the time (t)

#### Slide 14 -Tekstslide

s,t-diagram vs v,t-diagram
Moving at a constant speed gives me these 2 graphs
Notice that the first is an s,t-diagram,
The second one is a v,t-diagram

#### Slide 15 -Tekstslide

s,t-diagram vs v,t-diagram
Moving at a constant acceleration gives me these 2 graphs
Notice that the first is an s,t-diagram,
The second one is a v,t-diagram

#### Slide 16 -Tekstslide

s,t-diagram vs v,t-diagram
Moving at a constant negative acceleration gives me these 2 graphs
Notice that the first is an s,t-diagram,
The second one is a v,t-diagram

#### Slide 17 -Tekstslide

Calculating forces (4.1)

#### Slide 18 -Tekstslide

Forces (no acceleration)
If the resultant force is 0 N, the object is not accelerating
The speed is constant

standing still is also a constant speed (0 m/s)

#### Slide 19 -Tekstslide

Forces (acceleration)
If the resultant force is + N, the object will accelerate
(+ means it is in the same direction as the movement)

#### Slide 20 -Tekstslide

Forces (deceleration)
If the resultant force is - N, the object will decelerate
(- means the resultant force is opposite to the direction of movement)

#### Slide 21 -Tekstslide

What kind of movement will happen in this situation?
A
constant speed to the left
B
constant speed to the right
C
acceleration to the left
D
acceleration to the right

#### Slide 22 -Quizvraag

What kind of movement wil happen here
A
constant speed downwards
B
constant speed upwards
C
deceleration downwards
D
deceleration upwards

#### Slide 23 -Quizvraag

On an object the following forces are acting:
50 N to the right
20 N upwards
75 N to the left
20 N downwards
What type of motion will happen?
A
acceleration upwards
B
acceleration to the right
C
acceleration downwards
D
acceleration to the left

#### Slide 24 -Quizvraag

Homework
• Study the glossary of 4.3
• Complete the exercises of 4.3 (p. 176-181)

Next lesson = homework check (4.1, 4.2 & 4.3)
+ Practice test
timer
10:00