units

0.13 units

Physics uses 4 base units: meter, kilogram, second and Coulomb

Multiple Select

Other prefixes you are likely to see in this class are (select all that might apply)

• Giga

• Mega

• deci

• nano

• micro

Coulomb Measures 

CHARGE
We won't see this till the spring.

Derived Units

All other units can be made from the base units.  Sometimes it's clear like a speed in m/s.  Other times, the derived unit gets its own name.  For example, forces are measured in Newtons, but a N is made of kg, m and s. 

Metric Prefixs

Changing Scale

In the lab we often measure mass in g, distance in centimeters, and time in ms. Therefore, we need to know how big those things are.

Multiple Choice

how many meters is 1 cm?

• 1000 m

• 100 m

• 0.01 m

• 0.001 m

centi

centimeters is like centi dollars, which we just call cents!  They are smaller than meters, just like cents are smaller than dollars.

Multiple Choice

How many seconds is a millisecond

• 1000 s

• 100 s

• 0.01 s

• 0.001 s

The prefix milli looks like the word for 1000 in most languages.  But it's 1/1000.  Milli is another small thing.

Multiple Choice

How many kg is 1 g?

• 1000 kg

• 100 kg

• 0.01 kg

• 0.001 kg

Kilograms are big so a few grams is less than a kilogram

Multiple Choice

Notice - when working with lab measurements (cm, g), to get to the base units (m, kg ) we usually have to ______

• multiply

• divide