Newton's First Law (2.3)

Paragraph 2.3

Newtons First Law
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Slide 1: Tekstslide
NatuurkundeMiddelbare schoolvwoLeerjaar 3

In deze les zitten 14 slides, met interactieve quizzen, tekstslides en 1 video.

Lesduur is: 60 min

Onderdelen in deze les

Paragraph 2.3

Newtons First Law

Slide 1 -Tekstslide

True or False, and explain;
When you stop cycling on your bycicle you slow down because there are no more forces.
timer
1:00

Slide 3 -Video

Newton's First Law

"When the resulting force is equal to 0, an object moves with a constant speed or is standing stil. "

Slide 4 -Tekstslide

Constant Speed

As long as the resulting force is equal to 0 then the speed will remain the same: 21,4 m/s

When you are cycling the muscle force is equal to the resistance. When this occurs the forces are in equilibrium.

Slide 5 -Tekstslide

Acceleration

When there is a resulting force on an object the object will accelerate, decelerate or change direction.

You can see that the velocity wil keep increasing as result when a person uses more muscle force.
When he stops excerting this force only the friction remains and the object will slow down.

Slide 6 -Tekstslide

So..
When the resulting force is 0 the velocity remains the same.
When the resulting force is more than 0 the velocity increases.
When the resulting force is less than 0 the velocity decreases.

Slide 7 -Tekstslide

State at what times in the graph there is an acceleration, deceleration and a uniform motion.
timer
1:30

Slide 8 -Open vraag

Driving forces and resisting forces
There are resisting forces
- Air friction
- Sliding resistance
- Rolling resistance
And driving forces
- Force of gravity
- Engine Force
- Muscle Force
Resulting Force Fres = Fdriving - Fresisiting

Slide 9 -Tekstslide

Reducing friction
Air resistance
- Streamlining
- Decrease the frontal area

Sliding resistance
- The mass of the object
- The 'smoothness'of the surfaces of the objects.

Rolling friction
- Harder/Flatter underground.
- Pressure of the tires

Slide 10 -Tekstslide

Which kinds or resistance do you experience when you are cycling?
A
Air resistance
B
Sliding resistance
C
Rollinf friction
D
All of them

Slide 11 -Quizvraag

A rain drop falls down with a constant velocity. On the raindrop the force of gravity is applied and air resistance (Fr,a). Which of the statements is true?
A
Fg= Fr,a
B
Fg > Fr,a
C
Fg < Fr,a
D
Fr,a increases

Slide 12 -Quizvraag

A truck accelerates (with a constant engine force) from 72 to 90 km/h. The resulting force:
A
remains the same
B
increases
C
Decreases
D
is 0

Slide 13 -Quizvraag

What happens to a box if the man stops pushing and the sliding resistance is gone (ignore the air resistance)?
A
The box will slow down until it comes to a complete stop
B
The box will keep sliding forever.
C
You can't say