Name: _______________________________________________ Date: _____________ Block: ____
Forces in Motion – (Chapter 6 Section 1) – Gravity and Motion
1. All Objects Fall with the Same Acceleration
Galileo proved that the ____________ of an object does not affect the ____________ at which it falls.
The ____________ does not affect the rate of ____________.
Objects fall to the ground at the ____________because the acceleration due to gravity is the
____________ for all objects.
The rate of acceleration due to gravity is ____________. (For every second it falls, it’s downward
velocity increases by 9.8 m/s.)
1 sec
V = 0 m/s
V = 9.8 m/s
2 sec
V = 19.6 m/s
3 sec
V = 29.4 m/s
Velocity of Falling Objects: (page 139 Math Break)
Formula: v = g x t
Change in velocity = acceleration due to gravity x time
1. A penny at rest is dropped from the top of a tall stairwell. What is the penny’s velocity after it
has fallen for 2 seconds?
2. The same penny as described above hits the ground in 4.5 seconds. What is its final velocity?
3. A boy standing on a high cliff dives into the ocean below and strikes the water after 3 seconds.
What is the boy’s velocity when he hits the water?
2. Air Resistance slows down Acceleration
Air Resistance – a ____________that opposes the ____________ of objects through ____________
Air resistance acts in the ____________ direction of ____________.
Force of air
resistance
Force of gravity
Net Force acting on the
object keeps it
accelerating
Amount of air resistance depends on the ____________ and ____________ of an object.
For example a sheet of paper has ____________ air resistance than a sheet of paper crumbled into a ball.
More air resistance
Less air resistance
Same amount of
gravitational force
The force of air resistance keeps ____________ as the object ____________.
At a certain point, the force of air resistance will ____________ the force of ____________ and the net
force will be ____________.
This is called ____________and the object no longer ____________ as it falls. It is the constant velocity
of a falling object when the ____________ of the ____________ force of air resistance ____________
the size of the ____________ force of gravity.
Air Resistance
Equals
Gravitational Force
Net Force = 0
Object continues
falling, but no longer
accelerates
3. Orbiting Objects are in Free Fall
Free fall occurs when there is no ____________ (in a vacuum or space.) Gravity is the only
____________ acting on the ____________.
Two motions combine to form orbiting, ____________and ____________.
The shuttle is in ____________all because the only force acting on it is ____________.
The horizontal motion came from the rocket’s engine that makes it want to go in a straight line.
The shuttle and the astronaut are continually falling in a ____________ path following the surface of
the Earth!
If the shuttle started moving ____________, it would go straight and fall out of orbit.
If the shuttle started moving ____________, it would begin to hit the Earth.
Gravity provides the ____________ force that keeps ____________ in centripetal motion.
4. Projectile Motion
Projectile motion is the ____________ path an object ____________ near the
____________ surface.
Two components combine to form projectile motion – constant ____________ motion and
____________ (acceleration due to gravity).
Constant Horizontal Motion
Acceleration due to
Gravity