(Homework kappale 2: 7, 9, 13 ja 15 katsotaan ketkä ovat tehneet)

Four fundamental forces
Gravity = painovoima, between objects with mass
Electromagnetism = sähkömagnetismi between objects with charge ( + or -)
Strong force = vahva voima between 
Weak force = heikko voima

Notebooks

QUANTITIES AND UNITS = SUUREET JA YKSIKÖT

Mathanticsin video yksiköistä ja SI-järjestelmästä: mathantics_intothemetricsystem 

Tehdään välillä muistiinpanot

A quantity is something we can measure

In the SI system Base quantities are:
time, mass, current, temperature, substance, intensity and length

and their units are:
s, kg, A, K, mol, Cd and m

Vector quantity has direction and magnitude ex. velocity, force
Scalar quantity has magnitude but doesn't have direction ex. mass, length 

This is how we write the unit of a quantity:

[t] = 1s ("the unit of time is second")
[m] = 1kg ("the unit of mass is kilogram")
[v] = 1m/s ("the unit of velocity is meter/second")

Jatketaan video loppuun

This is how we change the unit:

1h = 60 min = 60*60s = 3600s
1km = 1000 m
1km/h = 1000m/3600s = 

Sometimes we have such a big numbers they are not easy to use
Esim. 2 s. 36

Alltogether ex. 2 and 8

Work with your pair and do ex. 5,6,7,10,11,17 use your books and/or internet

Vaihtoehtoisesti
Video (suureet, yksikkömuunnokset ja merkitsevät numerot 9 minuuttia)