What is the
difference
between mass
and weight?
Mass
O Quantity of matter
O Measured with a balance
O How much “stuff” is there
O Constant
Weight
O Measure of force of gravity
O Measured with a spring scale
O Changes depending on where you are
Weight Changes
O Weight depends on the mass of the two
objects. For Example: Earth is a lot more
massive than other planets, therefore the
force of gravity pulling us to it is larger, even
though we don’t really feel it. Weights
change on different planets depending on
size. Would we weigh less on the moon, or
Earth?
The Moon!
O Now, would we have a
different mass reading for
both places?
What is the
difference
between
temperature and
heat?
Temperature vs. Heat
O Temperature: measure of average kinetic
energy of particles
O Heat: a form of energy that can change the
movement of particles, or increase the
temp.
Temperature
O Measured in Celsius degree or Kelvin in
Chemistry
O Measured with a thermometer
Heat
O Results from temperature difference
O Measured in joules or calories
O Measured with a calorimeter
Let’s Look at These Closer..
O Place one hand on the top
of your desk, and one
hand on the leg of the
desk. Which feels colder?
Probably the Metal, but why?
O Metal is a great conductor. It will steal warm
energy from your body and move it
throughout the metal. The heat is spread out
and therefore makes the desk appear
colder.
Is the metal actually colder?
O No, it has been in the same room as the top
all day, so they both have the same
temperature, just a different way of
adjusting to the temperature of your body
when your hands are placed on both
materials.
Why does it take your energy?
O The desk is trying to reach equilibrium
between your body temperature and the
temperature that it is in the room.
O Heat always flows from a warmer region to a
cooler region.