Lesson 10 Chapter 4

• Physics
• Middelbare school
• vwo
• Leerjaar 3

Force and motion

This lesson

• Classical mechanics
• Distance time graphs
• Speed time graphs
• Key formula's
• Quantities and units exercise
• Practice exercise

Distance time graphs

Shows:

• The distance traveled

• How much time this took

•  How this distance was traveled

Which of the two is faster?

•  The gradient of the slope shows the speed of a movement
•  blue is faster

A

B

What happens in segments 

A & B?

What kind of movement does each graph show?

A: Constant speed

B: Constant speed – In the other direction

C: Stationary

D: Acceleration

E: Decceleration

Speed-time graphs

Shows:

• the speed something is traveling it.
• The gradient of the graph shows the acceleration.
• The area under the graph gives you the distance covered.

Lesson 10 Chapter 4

Key formula's for force and movement.

v=​t​​d​​

a=​t​​v​f​​−v​i​​​​

F=m⋅a

W=f⋅s

Speed

acceleration

Newtons second law of motion

Work

Key formula's for force and movement.

v=​t​​d​​

a=​t​​v​f​​−v​i​​​​

F=m⋅a

W=f⋅s

Speed

acceleration

Newtons second law of motion

Work

Inertia

physical quanitity	Symbol for the physical quantity	unit	symbol for unit
distance
		seconds
		meter/second
	Δv
accelration
			kg
	F
displacement
Work

physical quanitity	Symbol for the physical quantity	unit	symbol for unit
distance	d	meters	m
time	t	seconds	s
speed	v	meter/second	m/s
change in speed	Δv	meter/second	m/s
accelration	a	meter/second squared	m/s 2
mass	m	kilogram	kg
force	F	Newton	N
displacement	s	meter	m
Work	W	Newton- meter	Nm

Practice problem

A professional cyclist with a mass of 85 kg goes from cycling at a regular speed to sprinting. A trainer is measuring their speed. At moment 1 they're cycling at a speed of 8.8 m/s. at moment 2, 7.6 seconds later they're cycling at a speed of 11.9 m/s.

The magnitude of the combined resistive forces of friction and air resistance during this acceleration have a magnitude of 41 Newton. Calculate the magnitude of the foward force the cyclist applies by paddling to oppose these resistive forces