Test 2 Flashcards
SI units are based on the
Decimal system
There is one base unit in SI for each property being measured
Meter-distance
Liter-volume
Gram-mass
For each base unit in SI there is a
Standard
Example of a standard
Staples
Power outlet
Bed size
Legos
Standards are necessary for
Measurement
An exact quantity that everyone agrees to use for comparison
Standard
Amount of stuff in an object
Mass
Amount of space an object takes up
Volume
The amount of stuff in a certain amount of space
Density
How hard gravity pulls on an object
Weight
1 kilometer
1000 meters
1 decimeter
.1 meter
5 milliliters
.005 Liters
Density is the:
Measure of the ___________
of different kinds of matter.
Compactness
Density is:
How much _______ is in a certain amount of ________.
Stuff
Space
How dense a substance is depends on:
How much mass the atoms have.
How closely packed the atoms are.
The less dense material will _______ in the denser material.
Float
Does ice or water have the tighter packed atoms?
Water because when it freezes it expands
Each substance has a density that is
Constant
Changing the amount of a substance __________ change the density.
Does not
Changing the shape of a substance ___________ change the density
Does not
If two objects have the same mass the denser one will be_________.
The smaller one
If two objects have the same volume the denser one will be __________.
Heavier
T or F
A dense object always weighs more than a not dense object
False
The SI system works in multiples of
10
___________ units are easier to work with than units based on halves and quarters.
Decimal
The standard for 1 meter is based on the speed of _________ in a vacuum.
Light
Density can predict floating but not __________ it.
explain
Density=
Mass / volume
Getting repetitive measurements that are close to the real value.
Accuracy
A more specific value that is closer to the real value. Another application is getting repetitive answers that are all close together.
Precision
2.15 g is more precise than 2.1 g
Only goes to the tenths place (22.1 g)
Can be more accurate, but not necessarily.
Electronic Balance
Can go to the hundredths place (22.17 g)
Because it goes more decimals, it is more precise. It also can be more accurate, depending on the user.
Triple Beam Balance
To read a graduate cylinder properly you need to
Read it at eye level on a flat surface
Read from the bottom of the meniscus (curve)
Graduated cylinder accuracy depends upon:
- material of cylinder
- diameter of cylinder
- person reading the cylinder
When an object is put into a fluid an upward force occurs. __________
This force is called _________
Buoyancy
Buoyant force
The buoyant force __________ __________ on a completely submerged object because as you go lower there is more pressure on both the top and the bottom of the object.
Doesn’t change
By knowing that________displaces 1 liter you can determine how many liters of water will be displaced by a certain weight object
2.2 pounds
To float the weight of water displaced must _______ the weight of the object.
equal
How _____ the object floats in the liquid is determined by the necessary volume of water to equal the weight of the object.
deep
The buoyant force ______ ________ on a completely submerged object because as you go lower there is more pressure on both the top and the bottom of the object. The difference is always the same because the height of the object itself hasn’t changed.
doesn’t change
The difference in pressure between the bottom of an object and the top of object creates a net _______ _______.
upward force
The net upward force opposes gravity and causes objects to seem to weigh ______
less
being in water doesn’t shut off ________
gravity
The buoyant force on an object equals the weight of the volume of the fluid displaced (pushed out of the way)
Archimedes Principle
The ________ of the object determines the buoyant force.
volume
How does a steel ship float?
if you formed a steel block into a large, hollowed-out bowl shape and put it in water it would displace a lot of water because of its shape being spread out. It would soon be able to displace enough water to equal the weight of the steel and it would float.
Why will a steel block sink?
a steel block is not able to displace enough water for the buoyant force to push on the block and make it float.
