Download Lecture Notes: Chapter 2 Motion

Lecture Notes: Chapter 2 Motion
Real World Application: Motion

Q: Are distance and time important in describing running events at the track-andfield meets in the Olympics? Explain?
Motion and Frame of Reference
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A __________________________________is needed to determine the
_______________________________.

Motion occurs when _________________________________________________
Q: Frame of reference picture: Using the picture on this slide what would you use
as your frame of reference?
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Relative Motion
 Q: If you are sitting in a chair reading this sentence, you are moving? How?

You are not moving relative to your desk or your school building,
__________________________________________________________________
______________________________________________________
 Scientists at NASA need to consider frames of reference because all objects in
space are in constant motion relative to earth. They can’t just send up a satellite
or spacecraft and expect it to be at the speed of the other objects.
Distance
 An important part of describing the motion of an object is to describe
____________________________________________________________.
 SI unit for distance is:
___________________ (
)
___________________ (
)
___________________ (
)
Displacement

Suppose a runner jogs to the 50-m mark and then turns around and runs
back to the 20-m mark.
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Q: What is the distance traveled?
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The runner travels ________ in the original
direction (north) plus _________ in the opposite
direction (south), so the total distance she
ran is ___________.

___________________ is the ___________________________________
of an object's change in position from the starting point.

Q: What is the displacement in the above example?
Speed and The Speed Formula
* Speed is the __________________________________________________________.
Speed Formula:
Calculating Speed
 The SI unit for speed is __________________________________________
Examples of units of speed:
Motion with Constant Speed
 Suppose you are in a car traveling on a nearly empty freeway. You look at
the speedometer and see that the car's speed hardly changes.
 ______________________________________. It’s like driving and your car is
in _______________ _______________.
Constant Speed
Graph:
Changing Speed

Usually_________________________________.

Think about riding a bicycle for a distance of 5 km, as shown.
Speed changing over Distance
Average Speed
 Average speed describes speed of ____________________________
___________________________________.
 Average speed is the _______________________________________
__________________________________________________.
 Q: If the total distance traveled was 5 km and the total time was 15 min, or
0.25 h. What is the average speed?
Answer the following question:
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Section 2.1 Velocity and Acceleration

Velocity_____________________________________________.

Q: How are speed and velocity different? How are they the same?
Acceleration, Speed and Velocity
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Acceleration is ________________________________________
____________________________________________________.

Acceleration occurs when an _____________________________
_________________________________________.
Speeding Up and Slowing Down
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If the acceleration is in the_________________________as the velocity the
______________________________________________________
____________________________________________________.
• ,

If the speed decreases, _________________________________________
____________________________________________________________
Calculating Acceleration
Acceleration can be calculated from the following equation:
Calculating Positive Acceleration
 Q: Suppose a jet airliner starts at rest at the end of a runway and reaches a
speed of 80 m/s in 20 s.

Formula:

Numbers Used:

Answer with correct units:
Calculating Negative Acceleration
 Q: Now imagine that a skateboarder is moving in a straight line at a constant
speed of 3 m/s and comes to a stop in 2 s.

Formula

Numbers Used

Answer with correct units
Answer the following questions
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Extra Problems!!!!!!!!!!
Find the speed of a mouse who runs 15 m in 5 sec.
Find the acceleration of a car that goes from 15 m/s to 45 m/s in 5 sec.
Find the acceleration of a bus that goes from 60 m/s to 0 m/s in 2 seconds!!!
What is force?
* A force is___________________________.
Balanced Forces

When___________________________________, the forces combine to form the
__________________________.

Forces on an object that are__________________________________________
Balanced Forces
Unbalanced Forces

When two students are__________________________ or ___________________
Unbalanced Forces
Inertia and Mass

Inertia (ih NUR shuh) is ____________________________________________.

The velocity of the object ____________________________________________

If an object is at rest, ________________________________________________.

The inertia of an object is related to its mass.
__________________________________________________________________
Newton’s Laws of Motion

The British scientist _______________________________(1642–1727) was able
to state rules that describe the effects of forces on the motion of objects.

Newton's first law of motion states that
__________________________________________________________________
_________________________________________________________________.

If an object is at rest, ________________________________________________.

This law is sometimes called ___________________________

Q: How can a car crash explain the law of inertia?
Questions
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