1. Motion

2. Frames of Reference
The object or point from which movement is determined
Movement is relative to an object that appears stationary
Earth is the most common frame of reference

3. Motion
Motion is a change in position relative to a frame of reference

4. Distance and Displacement
Distance is how far you travelled
Displacement is how far you are from the starting point, plus a direction.

5. Quick Quiz
The diagram below shows the position of a cross-country skier at various times. At each of the indicated times, the skier turns around and reverses the direction of travel. In other words, the skier moves from A to B to C to D. Use the diagram to determine the resulting displacement and the distance traveled by the skier during these three minutes.

6. Answer The skier covers a distance of
(180 m m m) = 420 m and has a displacement of 140 m.

7. Speed The units for speed:
Speed is the distance traveled in a given amount of time
Speed=distance
time
The units for speed:
meters/second (m/sec)
kilometers/hour (km/hr)
Speed that does not change is constant speed

8. Practice Problem
A runner completes a 400-m race in 43.9s. In a 100-m race, he finishes in 10.4 s. In which race was his speed faster?
400m  43.9s =
100m  10.4s =
What is the formula for speed?
9.1m/s
9.6m/s
 FASTEST

9. Distance v. Time represents the motion of an object
time is plotted on the horizontal axis and distance is plotted on the vertical axis
can be used to compare the speeds of objects

10. Average speed Total distance divided by the total time Formula:

11. Velocity
Speed in a given direction

12. Acceleration The change in velocity
Acceleration is measured in m/sec/sec or m/sec2
Formula is:

13. 3 ways to Accelerate Speed Up- Positive Acceleration
Slowing Down- Negative Acceleration
Change Direction

14. Acceleration Graph
Speed vs Time

15. Centripetal Acceleration
Acceleration directed toward the center of circular path

16. Momentum
Momentum is the quantity of motion of a moving body, measured as a product of its mass and velocity
Inertia is a property of Matter. (Thanks Bill)
Inertia is an objects resistance to change. (in motion or not in motion).
The more mass an object has the greater its inertia

17. Momentum
Momentum is equal to the mass of an object times its velocity
momentum= mass x velocity

18. Conserving Momentum
The law of conservation of momentum states that the total momentum is NOT lost, only transferred

19. 1. The hulk coaster at Universal’s Islands of Adventure shoots out of a tunnel going from 0 mps to 80 mps in 4 seconds. What is its acceleration?
2. A race car is speeding down the Talladega Raceway behind the pace car at 90 mph. When the pace car drives off the track, the race car accelerates to 210 mph in .01 hour. What is its acceleration?
3. A runner in a 5K (5000m) race paces himself. His time at the end of the race is 25 minutes. What is his speed?
4. A jet plane has flown from Boston to New York, a distance of 330 miles, in 15 minutes. What was its speed?

20. Newton’s Laws of Motion
I Law of Inertia
II F=MA
III Action-Reaction

21. Newton’s Laws of Motion
1st Law – An object at rest will stay at rest, and an object in motion will stay in motion at constant velocity, unless acted upon by an unbalanced force.
2nd Law – Force equals mass times acceleration.
3rd Law – For every action there is an equal and opposite reaction.

23. 1st Law- Law of Inertia
Inertia is the tendency of an object to resist changes in its velocity: whether in motion or motionless.

25. Partner
Why then, do we observe every day objects in motion slowing down and becoming motionless seemingly without an outside force?

26. Objects on earth, unlike the frictionless space the moon travels through, are under the influence of friction.

27. What is this unbalanced force that acts on an object in motion?
Friction!
There are four main types of friction:
Sliding friction: ice skating
Rolling friction: bowling
Fluid friction (air or liquid): air or water resistance
Static friction: initial friction when moving an object

28. Newtons’s 1st Law and You
Because of inertia, objects (including you) resist changes in their motion. When the car going 80 km/hour is stopped by the brick wall, your body keeps moving at 80 m/hour.

29. 1st Law and Net Force
Net force is the overall force (unbalanced) acting on an object causing it to accelerate in a direction.
In these scenarios which way will the block move?

31. 2nd Law
F = M x A

32. 2nd Law
When mass is in kilograms and acceleration is in m/s/s, the unit of force is in newtons (N).
One newton is equal to the force required to accelerate one kilogram of mass at one meter/second/second.

33. Newton’s 2nd Law proves that different masses accelerate to the earth at the same rate, but with different forces.
We know that objects with different masses accelerate to the ground at the same rate.
Earth’s Gravity pulls all objects towards Earth at 9.8m/s/s

35. 3rd Law
For every action, there is an equal and opposite reaction.

36. The 3rd law includes 2 forces acting against each other
The 3rd law includes 2 forces acting against each other. These two forces are called action and reaction forces.
3rd Law

37. 3rd Law
The reaction of a rocket is an application of the third law of motion. Various fuels are burned in the engine, producing hot gases.
The hot gases push against the inside tube of the rocket and escape out the bottom of the tube. As the gases move downward, the rocket moves in the opposite direction.