1. May 1, 2018 Mental Math…be ready. You need: Clean paper (2) / pencil
Warm Up:
Mental Math…be ready.
I CAN: demonstrate unbalanced and balanced forces with magnets.
I CAN: show a transfer of energy through electrical circuits.

2. Today’s agenda Mental Math Reminders/calendar
Review simple machines and Newton.
Magnets and Circuits

3. Swagrrr No 7th test ELA 7 Math 7 Math I
May 2018
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Forces and energy
Magnets 1
Magnets / eclectricity 2
Electricity 3
Catch up 4
Review
Test Assess
MobyMax Milkshakes 5 6 7
Atmosphere 8 9 10 11 12 13
Mother’s Day 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
No School
Memorial Day 29 30 31
APRIL 30
Progress reports
Swagrrr
No 7th test
ELA 7
Math 7
Math I

4. June 2018 EOG testing ELA 7 Math 7 Math I Busch Gardens NCFE SS/Sci 7
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday 1
Atmosphere 2 3 4 5 6 7
8 Last day (due to snow) 9
EOG testing
ELA 7
Math 7
Math I
Busch Gardens
NCFE SS/Sci 7
NCFE testing

5. Simple Machines (Making work easier…phew!)
REVIEW

6. Simple Machines Foldable
8 Simple Machine Notes
7 Lever
6 Pulley
5 Wheel & Axle
4 Wedge
3 Screw
2 Inclined Plane
1 Title Tab
Simple
Machines
By John Smith
REVIEW
Line up your papers about 1-2 cm apart
Fold the papers over.
Number and title each flap

7. REVIEW How do machines do work?
Machines make work easier by changing 3 things about the FORCE you exert to do work:
AMOUNT OF FORCE you exert
DISTANCE over which you exert
force
DIRECTION in which you exert force

8. What are SIMPLE MACHINES?
REVIEW
There are only 6 basic simple machines that make work easier:
Inclined Plane
Wedge
Screw
Lever
Wheel & Axle
Pulley

9. REVIEW COMPOUND MACHINES
Compound Machines – are made of combinations of two or more simple machines.
For example, a simple can opener is a combination of 3 simple machines:
Lever
Wheel & axle
Wedge

10. REVIEW WORK & SIMPLE MACHINES
Simple machines DON’T change the amount of WORK done!
(They change the size, distance or direction of your FORCE!)
WORK IN = WORK OUT*
(*usually machines lose a bit of work due to FRICTION…)

11. What is the mechanical advantage of a machine?
REVIEW
A machine’s mechanical advantage is the number of times a machine increases a force exerted on it.
Mechanical = Output Force Advantage Input Force

12. What is the mechanical advantage of a machine?
REVIEW
You exert 10 N of force on a can opener. The can opener exerts 30 N of force on the can. What is the mechanical advantage?
Mechanical = Output Force = 30 N
Advantage Input Force N
Mechanical Advantage = 3

13. What is the efficiency of a machine?
REVIEW
The EFFICIENCY compares:
the work you put IN to
the work the machine puts OUT.
An IDEAL machine is 100% efficient.
INPUT WORK = OUTPUT WORK
In the real world, some input work is always lost due to FRICTION between the moving parts of the machine.

14. What is the efficiency of a machine?
REVIEW
EFFICIENCY = Output Work x 100% Input Work
You mow the lawn with a rusty lawn mower. You do 50,000 J of work on the lawn mower but only 25,000 J go to cutting the lawn. What is the efficiency of the lawn mower?

15. What is the efficiency of a machine?
REVIEW
You mow the lawn with a rusty lawn mower. You do 50,000 J of work on the lawn mower but only 25,000 J go to cutting the lawn. What is the efficiency of the lawn mower?
EFFICIENCY = Output Work x 100% Input Work
Efficiency = 25,000 J x 100%
50,000 J
Efficiency = 50%

16. Try these problems on your own…
REVIEW
Mechanical = Output Force Advantage Input Force
EFFICIENCY = Output Work x 100% Input Work

17. Making a foldable: Newton’s Laws of
Making a foldable: Newton’s Laws of Motion On the inside, include the following info for each law: 1) What does the law say? 2) What’s an example of a situation that shows the law in action. 3) Draw a picture that shows the law in action.
NEWTON’S
LAWS
Newton’s First Law of Motion
Newton’s Second Law of Motion
Newton’s Third Law of Motion

18. THE LAW OF
Newton’s 1st Law
INERTIA

19. Newton’s 1st Law of Motion
Newton’s 1st law of motion states:
An object at rest will remain at rest,
-and-
an object moving at a constant velocity will continue moving at a constant velocity,
-UNLESS-
it is acted upon by an unbalanced force.

20. THE LAW OF
Newton’s 2nd Law
Acceleration

21. Newton’s 2nd Law of Motion
Newton’s 2nd law of motion describes how UNBALANCED FORCES and MASS affect the ACCELERATION of an object.

22. Newton’s 2nd Law of Motion
It states:
ACCELERATION depends on the object’s MASS, and the net FORCE acting on the object.
We can also write it mathematically:
Force = Mass x Acceleration

23. Try one on your own…
Ms. Litwak’s van runs out of gas. How much force does she need to push the 2000kg van at an acceleration of 0.5 m/s2?
0.5 m/s2
F = m x a
F = 2000 kg x 0.5 m/s2
F = 1000 N right

24. Newton’s 2nd Law of Motion
Speed, Distance & Time
We can also write the formula like this:
Acceleration = Force
Mass
Mass = Force
Acceleration
Force = Mass x Acceleration m F a

25. THE LAW OF
Newton’s 3rd Law
Interaction

26. Which forces are acting to get this guy up in the air?
His feet push DOWN on the ground.
But wait… His downward push can’t be causing his upward motion.

27. Which forces are acting to get this guy up in the air?
His feet push DOWN on the ground.
The ground pushes UP on the man.
There must be a force pushing UP!
The force of the ground pushes him UP!

28. Newton’s 3rd Law of Motion
Newton’s 3rd law says that: For every action force, there is an equal and opposite reaction force.
ALL forces act in PAIRS!
Action Force: Man’s feet push DOWN on the ground.
Reaction Force: Ground pushes UP on the man.

29. Identify the force pairs in each situation
A space shuttle lifts off.
Action Force – engine pushes gases down & out.
Reaction Force – the gases push the rocket up.
*This upward force must be stronger than gravity pulling down on the rocket!

30. Identify the force pairs in each situation
A person stands still.
Action Force – gravity pulls the person down to the floor.
Reaction Force – the floor pushes up on the person.
*You don’t need MOTION for force pairs. They are everywhere!

31. What is Momentum? Momentum is a measure of how much motion object has.
It is affected by mass and velocity. The heavier an object is, the more momentum it has.
It’s easier to stop soccer ball coming towards you at 20 m/s than a car coming at 20 m/s.
It’s easier to stop car travelling at 1 km/h than a car travelling 60 km/h!

32. Conservation of Momentum
When objects collide, their total momentum is conserved (stays the same), unless outside forces act.
The total amount of motion coming into a collision will also come out of the collision.

33. Place 4 coins in a row, touching each other.
Place the 5th coin about 2 inches away from the end of the row, keeping it in line.
Lightly flick your finger forward, propelling the single coin against the others.
What do you observe?
Try it again, flicking 2 coins into a row of 3 coins. What do you observe?

34. Momentum = mass x velocity
Momentum can be calculated using this formula:
Momentum = mass x velocity
A golf ball with a mass of 0.05 kg travels at 16 m/s.
A baseball with a mass of 0.15 kg travels at 7 m/s.
Which ball has the greater momentum?
Golf ball’s momentum = 0.05 kg x 16 m/s
Baseball’s momentum = 0.15 kg x 7 m/s
= 0.8 kg m/s
= 1.05 kg m/s

35. Magnets
What do you already know?
List at least three things

36. Magnets
Work with your elbow partner (so you can use the ONE desk – not across the desks).
Use the marble and magnet. What can you do? Why? WRITE IT DOWN!
Using the terms balanced and unbalanced forces, write three sentences about your magnet investigation.

37. Magnets Magnets create unbalanced forces.
Magnets can use that unbalanced force to create motion…for certain metals.
Magnets can therefore cause acceleration (change in speed or direction).
Magnets are related to Earth.
Magnets are related to positive and negative charges – like electricity.

38. Circuits

39. Let’s act it out! Make a circle = CIRCUIT What can you figure out?
Follow this with an energy ball (or start with the energy ball?)

40. Electricity
It is the flow of the ELECTRONS that we call electricity. An electron is one of the tiny particles within an atom. An atom is the smallest thing that is still recognized as a basic element (not just a part or piece of something larger).

41. Electricity It is the flow of the ELECTRONS that we call electricity.
This flow of electrons is how the current is approximately measured. Can you count how many electrons flow past a given point in one second?
One COULOMB is about:
6 x 1018
6, 000,000,000,000,000,000
6 quintillion
One AMPERE (Amp) is really one coulomb of electrons going past a point each second.

42. Key Vocabulary
Electricity: A source of power generated from the flow of electrical current.
Electron: A small, atomic particle with a negative charge.
Energy: The ability to do work.

43. Key Vocabulary
Circuit : A path through which electrical current can flow.
Circuit Diagram : An illustrative picture used to explain the paths through which electricity can flow.
Conductor: A material that allows for electrical current to flow.
Current: The flow of electrons through a conductor.

44. Circuit
Just examples – two “easy” or “simple” and two that are…not.

45. Electrical shorthand We have created a “short-hand” or a way to draw out circuits using symbols.
Bulb/lamp/light – can be used as an indicator to simply show there is electrical flow OR may be the main purpose for the circuit
Bulb

46. Electrical shorthand
Wire/wiring – the connection between parts, allows for flow (and extension over distances), must be a CONDUCTOR, typically is covered with INSULATION to protect those who may come in contact.

47. Negative Positive Electrical shorthand Battery
Power source - in simple circuits that power source is most likely a battery.
Battery
Negative
Positive

48. Electrical shorthand Switch - closed (allows flow)
Switch - open (stops flow)

49. Electrical shorthand Motor Buzzer
Sometimes you may want to add in a motor or a buzzer (sound maker)…
Motor
Buzzer

50. Let build! – Simple Circuit
1st DRAW out a simple circuit with one bulb and one battery.
2nd BUILD your simple circuit = try to make your bulb light up.
3rd DRAW / WRITE = what worked and why, what did not work and why.
BONUS: Can you create / add in a switch?

51. Clean up!
Your “creation” should be drawn on your paper – so you aren’t losing the info/design.
All supplies OFF of the “circuit board”
Wires / bulbs should be separated (not wound together)
Wires / bulbs go back into the cup
Tape should be put around the outside of the cup

52. What if I have a need for more lights?
I want to have three lights over my dinner table. Can you create a circuit to help?
EXTENSION: this is great for those who can move ahead while waiting for others to finish.

53. Let build! Series Circuit
1st DRAW out a series circuit with multiple bulbs and ONE battery.
2nd BUILD your series circuit = try to make your bulbs light up.
3rd DRAW / WRITE = what worked and why, what did not work and why.

54. But…
If ONE bulb burns out, I don’t want to lose all three. How do I fix that?

55. Let build! Parallel circuit
1st DRAW out a parallel circuit with multiple bulbs and ONE battery.
2nd BUILD your parallel circuit = try to make your bulbs light up.
3rd DRAW / WRITE = what worked and why, what did not work and why.

56. Clean up!
Your “creation” should be drawn on your paper – so you aren’t losing the info/design.
All supplies OFF of the “circuit board”
Wires / bulbs should be separated (not wound together)
Wires / bulbs go back into the cup
Tape should be put around the outside of the cup

57. Let discuss Share what you built
What would happen if the battery were turned around in the circuit?
Which would be brighter…light bulbs in series or light bulbs in parallel? Why?
Briefly describe the differences between a parallel and a series circuit.