1. Quarter 4 Review

2. Motion is defined as the state in which the distance from another object is changing.
Motion is typically determined by use of stationary reference points.
Reference points are a place or object used for comparison to determine if something is in motion.
Stationary or permanent, fixed objects make good reference points because their position is fixed, it doesn’t change.
Moving objects make poor reference points because objects in motion make it difficult to determine the motion of another object.

3. Speed is measured as: a change in distance per change in time time
What are some things you can think of that are measured like this?

4. SPEED
Speed is the distance that an object travels in a period of time. d t v
Units are meters and seconds (and therefore meters per second). However, sometimes km/hr is more sensible.
A cyclist travels 25 km in ½ an hour.
What is their speed - in kmhr-1
- in ms-1
Meters per second
= ms = m/s = ms-1
H/O activity 18.2 Running speeds
H/O Bubble gum champ
= 25km/0.5hr = 50km/hr
= 25000m/1800s = 13m/s

5. SPEED GRAPHS What would these look like on a distance/time graph?
1. stopped
2. slow
3. fast
4. accelerating

6. Speed in a given direction is VELOCITY
When you know both the speed and direction of a object’s motion, you know the velocity of the object.
Speed in a given direction is VELOCITY

7. Acceleration is a change in velocity (speed).
Scientists have a special way to measure a change in speed or velocity:
Acceleration
Acceleration is a change in velocity (speed).

8. Acceleration
in everyday terms it’s described as the process of “speeding” up.
Scientifically it is the rate a which velocity changes.
Velocity is speed in a given direction and can change in 3 ways.
Increase speed
Decrease speed
Change directions
Deceleration is “negative” acceleration.

9. Acceleration is measured as:
a change in speed per period of time
Final speed – initial speed
time
Acceleration is measured in m/s/s or m/s²
This measures how many meters per second an objects moves in a second

10. ACCELERATION GRAPHS What would these look like on a speed/time graph?
1. stopped
2. slow
3. fast
4. accelerating

11. Only a force can change the velocity of an object.
Nothing will change speed unless acted upon by a force. If it’s sitting still, it will keep sitting still. If it’s moving fast, it will keep moving fast.
Only a force can change the velocity of an object.

12. Force A force is a push or a pull.
Force gives an object the energy to move, stop moving, or change direction.
When you write with a pen you exert a force. When you peddle your bike, blow your nose, turn on a faucet, chew your gum, or swimming in a pool, you are exerting forces on other objects.
We would never be able to move without exerting forces on things.
                      
       
            

13. Law of Inertia
Inertia- the tendency of an object to resist a change in motion.
This law is the same reason why you should always wear your seatbelt.

14. If objects in motion tend to stay in motion, why don’t moving objects keep moving forever?
Things don’t keep moving forever because there’s almost always an unbalanced force acting upon it.
A book sliding across a table slows down and stops because of the force of friction.
If you throw a ball upwards it will eventually slow down and fall because of the force of gravity.

15. Magnetic Forces Magnetic forces are produced by magnetic poles.
Ch 36 Magnetism Notes
Magnetic Forces
Magnetic forces are produced by magnetic poles.
Every magnet has both a North and South pole.
Like poles repel, unlike poles attract.

16. Electric Currents & Magnetism
Ch 36 Magnetism Notes
Electric Currents & Magnetism
Since moving charges create magnetic fields, an electric current creates a magnetic field.
A coil of wire can concentrate the magnetic field and create an electromagnet.

17. What is ENERGY? Energy is the ability to do work.
Everything that happens in the world uses
energy!
Most of the time we can’t see energy, but it is
everywhere around us!

18. Energy… is NEVER created or destroyed!
can only be STORED or TRANFERRED.

19. How is all energy divided?
Potential Energy
Kinetic
Energy

20. Potential Energy is… The energy stored in an object.
"Potential" simply means the energy has the ability to do something useful later on.

21. The higher an object, the more potential energy.
The more mass an object has, the more potential energy it has.

22. Potential Energy Converted to Kinetic Energy…
When stored energy begins to move, the object now transfers from potential energy into kinetic energy.

23. Kinetic Energy Is… The energy of a moving object.
"Kinetic" means movement!
When stored energy is being used up, it is making things move or happen.

24. The faster the object moves, the more kinetic energy is produced.
The greater the mass and speed of an object, the more kinetic energy there will be.

25. An object has the MOST kinetic energy when it’s movement is the GREATEST.
When an object has the LEAST potential energy, it has the MOST kinetic energy.

26. Energy Energy is the ability to do work.
Energy is anything that can make matter move or change.
Some forms of energy include:
Mechanical (kinetic and potential)
Thermal (heat)
Chemical
Electrical
Electromagnetic
Sound
Light
Nuclear

27. What is Mechanical Energy?
Energy due to a object’s motion (kinetic) or position (potential).
The bowling ball has mechanical energy.
When the ball strikes the pins, mechanical energy is transferred to the pins!

28. What is Electromagnetic Energy?
Light energy
Includes energy from gamma rays, xrays, ultraviolet rays, visible light, infrared rays, microwave and radio bands

29. What is Chemical Energy?
Energy that is available for release from chemical reactions.
The chemical bonds in a matchstick store energy that is transformed into thermal energy when the match is struck.

30. What is Thermal Energy?
Heat energy
The heat energy of an object determines how active its atoms are.
A hot object is one whose atoms and molecules are excited and show rapid movement.
A cooler object's molecules and atoms will show less movement.

31. Energy Transfer Sound (mechanical) Electrical Thermal Mechanical
Chemical
Electrical
Light
(Electromagnetic)

32. A Basic Circuit All electric circuits have three main parts
A source of energy
A closed path
A device which uses the energy
If ANY part of the circuit is open the device will not work!

33. Ways to Wire Circuits
There are 2 basic ways to wire a circuit. Keep in mind that a resistor could be ANYTHING ( bulb, toaster, ceramic material…etc)
Series – One after another
Parallel – between a set of junctions and parallel to each other

34. What is Work?
In Science, the word WORK has a different meaning than you may be familiar with.
The scientific definition of work is: Using a force to move an object a distance (when both the force and the motion of the object are in the same direction.)

35. How do we Work? Energy: Ability to do Work. Work = Force x Distance
Force is a Push or a Pull.

36. Example: Calculation of Work
Work = Force x Distance.
Calculate: If a man pushes a concrete block 10 meters with a force of 20 N, how much work has he done?
200 Joules. (W=20N x 10m).

37. Simple Machines
A machine is a device that helps make work easier to perform by accomplishing one or more of the following functions:
Transferring a force from one place to another.
Changing the direction of a force.
Increasing the magnitude of a force, or increasing the distance or speed of a force.

38. Mechanical Advantage
It is useful to think about a machine in terms of the INPUT FORCE (the force you apply) and the OUTPUT FORCE (force which is applied to the task).
When a machine takes a small input force and increases the magnitude of the output force, a MECHANICAL ADVANTAGE has been produced.

39. Mechanical Advantage
Mechanical advantage is the ratio of output force divided by input force. If the output force is bigger than the input force, a machine had a mechanical advantage greater than one.
If a machine increases an input force of 10 pounds to an output force of 100 pounds, the machine has a mechanical advantage (MA) of 10.

40. Mechanical Advantage
In machines that increase distance instead of force, the MA is the ratio of the output distance and input distance.
MA= output/input

41. Inclined Plane
An inclined plane is an even sloping surface. The inclined plane makes it easier to move a weight from a lower to higher elevation.

42. The Lever
A lever is a rigid bar that rotates around a fixed point called the fulcrum.
The bar may be straight or curved.
In use, a lever has both an effort (or applied) force and a load (resistant force).

43. Wheel and Axle
The wheel and axle is a simple machine consisting of a large wheel rigidly secured to a smaller wheel or shaft, called an axle.
When either the wheel or axle turns, the other part also turns. One full revolution of either part causes one full revolution of the other part.

44. Pulleys Pulley are wheels and axles with a groove around the outside.
A pulley needs a rope, chain or belt around the groove to make it do work.

45. Review Simple Machine Mechanical Advantage Efficiency Inclined Plane
Length of Slope
Height of Plane
Efficiency = work output
work input X 100
Pulley
The Mechanical Advantage of a pulley is equal to the number of ropes supporting the pulley.
work input X 100
Lever
Distance of Effort to Fulcrum
Distance of Load to Fulcrum
Wheel and Axle
Radius of Wheel
Radius of Axle
work input X 100