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Gravity - pp. 326-329 in blue science book
NEWTON
center of Earth.
1. ___realized that a force acts to pull objects straight down toward the
GRAVITY
2. ___is the force that pulls objects toward each other.
FREE FALL
3. When the only force acting on a falling object is gravity, the object is
said to be in ___ ___.
9.8 m/s2
4. The acceleration rate due to the force of gravity is ___ ___/___.
PROJECTILE
5. An object that is thrown is called a ___.
AIR RESISTANCE 6. What is the main reason all objects do not fall at the same rate on Earth?
TERMINAL VELOCITY 7. The greatest velocity the object reaches as it falls is called ___ __.
WEIGHT
8. ___ is a measure of the force of gravity on an object.
MASS
9. ___ is a measure of the amount of matter in that object.
LAW OF UNIVERSAL GRAVITATION 10. The ___ ___ ___ ___ states that the force of
gravity acts between all objects in the universe.
MASS
11. Your ___ will remain the same on another planet or moon.
WEIGHT
12. Your ___ will be different due to different gravitational forces.
13. The gravitational force, or pull, depends on two things.
a. The MASS
of the two objects
b. The DISTANCE
between the two objects
(Over)
Friction – pp323-325 in blue science book
UNBALANCED
1. A book’s motion only changes if an ___ force acts upon it.
FRICTION
2. When a book slides, the force of ___ causes it to slow to a stop.
GRAVITY
downward.
3. When a book falls, the force of ___ causes it to accelerate
IRREGULARITIES
many ___.
4. Although surfaces may seem quite smooth, they actually have
FRICTION
5. The force that one surface exerts on another when the two rub
against each other is called ___.
FRICTION / FOREVER 6. Without ___, the object would continue to move at a constant
speed ___.
7. The strength of the force of friction depends on two factors:
a. the TYPES
of surfaces involved and
b. how HARD
the surfaces PUSH
ROUGH
together.
8. ___ surfaces produce greater friction than smooth surfaces.
FORCEFULLY
9. If you rub your hands together ___, there is more friction than
if you rub your hands together lightly.
NO!
10. Is friction necessarily a bad thing?
SLIDING FRICTION 11. When solid surfaces slide over each other, the kind of friction
that occurs is called ___ ___.
ROLLING FRICTION 12. When an object rolls over a surface, the kind of friction that
occurs is ___ ___.
FLUID FRICTION
13. The friction that occurs when an object moves through a
liquid or a gas is called ___ ___.
FLUID FRICTION
14. Of the 3 types of friction listed above (11, 12, 13), which one
usually requires the least amount of force to overcome?