1. 5th Six Weeks Review

2. POTENTIAL ENERGY
&
KINETIC ENERGY
REVIEW

3. The Law of Conservation of Energy
Energy can not be ________ or ________ it can only be converted from one form of energy to another.
The total amount of energy in the universe remains ________!
created
destroyed
constant

4. Revisiting Newton’s 3rd Law of Motion
Newton’s 3rd law states that for every ____________ force there is an equal and opposite ____________ force.
ACTION
REACTION

5. Newton’s 3rd Law of Motion

6. Newton’s 3rd Law of Motion
A student throws a ball while standing on a skateboard. Which direction will the student go after he releases the ball? A. B. C.

7. Potential Energy
Potential energy is ___________ energy waiting to be ______________.
STORED
RELEASED
The man and the apple both have potential energy due to position.

8. Gravitational Potential Energy
GPE = mass X 9.8 m/s2 X height
Rate of acceleration due to gravity. All objects falling under the force of gravity, will fall at 9.8 m/s2.

9. Gravitational Potential Energy

10. Gravitational Potential Energy

11. The velocity does because its value is squared
KINETIC ENERGY
KINETIC ENERGY IS ENERGY THAT IS IN ______________.
MOTION
K.E. = mass x velocity2 2
K.E. = m X v2
What has a greater affect of kinetic energy, mass or velocity? Why?
The velocity does because its value is squared

12. Which has more kinetic energy, a large dog sitting on a sidewalk or a small cat running down the street?
The large dog
The small cat
Both have the same kinetic energy
Need more information to answer

13. THERMAL ENERGY REVIEW

14. 1. Conduction 2. Convection 3. Radiation COLD HOT
Energy moves from a hotter to a colder object by one of the three mechanisms:
1. Conduction
2. Convection
3. Radiation
COLD
HOT

15. ConDuction
Conduction is the transfer of thermal energy through matter by the DIRECT contact of particles.
irect
Heat energy
SOLIDS are most effective at conducting heat because their particles are closer together.

16. Convection
Convection is the transfer of thermal energy in a FLUID by the movement of the heated particles.
Liquids are fluids. HOT liquid is less dense so it RISES, COLD liquid is more dense so it SINKS.
Gases are fluids. HOT gas is less dense so it RISES, COLD gas is more dense so it SINKS.

17. A lizard uses radiant energy to help control body temperature
Radiation
Radiation is the transfer of thermal energy by electromagnetic waves that can travel through space even when no matter is present.
A lizard uses radiant energy to help control body temperature
FIRE

18. QUICK REVIEW

19. Show me what you have learned!

20. The heat provided by the heating system warms up the room primarily by _________.
Conduction
Convection
Radiation

22. Thermal energy is transferred from the pot to spoon by ________.
Conduction
Convection
Radiation

24. Thermal energy is transferred from the sun to “Vacation Santa” by _________.
Conduction
Convection
Radiation

26. NONRENEWABLE RESOURCES
&
NONRENEWABLE RESOURCES

27. A renewable resource is an energy source that is REPLACED nearly as quickly as it is used.
Wind
Sun
FEW POLLUTUTANTS
Water

28. Coal Petroleum Natural Gas
A nonrenewable resource is an energy source that CAN NOT be REPLACED by natural processes as quickly as they are used.
Coal
Petroleum
Natural Gas
MANY POLLUTUTANTS

29. Solar cell

31. WORK & SIMPLE MACHINES
REVIEW

32. Work
Work is the transfer of energy that occurs when a force makes an object move.
Work = Force X distance
W = F X d W F d

33. Calculate the work needed to lift a TV weighing 6 newtons a distance of 2 meters.
12 Joules W 6 2 X

34. If a weight lifter is holding barbells above his head, what does he have to do to perform work?
stand still
move barbells sideways
step forward
lower barbells

35. Power
Power is the amount of work done in a certain amount of time. It is the rate at which work is done.
Power = Work / time
P = W / t P t W X

36. How much power is required to do 10 joules of work in 5 seconds?
2 Watts

37. Efficiency
Efficiency is the measure of how much of the work put into a machine is changed into useful output work by the machine.
Work output is ALWAYS less than work input!
Efficiency = (work output / work input) X 100%
Efficiency = (Wout / Win) X 100%

38. Efficiency = (Wout / Win) X 100%
Efficiency = (80 / 320) X 100%
Efficiency = 25%

39. All machines are less than 100% efficient
All machines are less than 100% efficient. Some energy is converted to thermal energy due to _________.
position
mass
friction
speed

41. Simple Machines

42. Levers

43. The human arm is an example of which class of lever?
First class
Second class
Third class
None of the above

44. A see saw is which class of lever?
First class
Second class
Third class
None of the above

45. Which lever requires the LEAST effort to lift the load?
The CLOSER the fulcrum is to the load, the easier it is to lift!

46. IMA = length of slope / height of slope
Mechanical Advantage
Calculating the mechanical advantage of an inclined plane.
IMA = length of slope / height of slope
IMA = l / h
Length of Slope
Height of Slope

47. What is the ideal mechanical advantage of this inclined plane?
840 48 3
1/3
IMA = l / h
IMA = 12 / 4
IMA = 3
Length of Slope
Height of Slope
12 m
4 m

48. Archimedes’ Principle Bernoulli’s Principle Pascal’s Principle
REVIEWING…….
Archimedes’ Principle
Bernoulli’s Principle
Pascal’s Principle

49. FLOAT Archimedes' Principle SINK
Archimedes’ principle states that the buoyant force on an object is equal to the weight of the fluid displaced by the object.
Buoyant force is the upward force exerted on an object by the fluid that it is immersed in.
SINK

50. Why does the rock in water weigh less than the rock in air?

51. Bernoulli's Principle FLIGHT
Bernoulli’s principle states that as the velocity of a fluid increases, the pressure exerted by the fluid decreases.
FLIGHT

52. According to Bernoulli, the faster a fluid flows the less pressure it exerts. In the diagram above, where is the air flow the slowest?
LOW pressure area
On the top
On the bottom
Top and bottom are the same
HIGH pressure area

53. Pascal's Principle PRESSURE
Pascal’s principle states that pressure applied to a fluid is transmitted throughout the fluid.
PRESSURE

54. Gas Laws Review
Boyle’s Law
Charles’ Law

55. Boyles’ Law Volume (size of container) Pressure
Gas particles will have MORE space to move around, so LESS pressure
Gas particles will have LESS space to move around, so MORE pressure

56. As the volume increases (y) the pressure decreases (x)

57. Charles’ Law Temperature Volume
Put a balloon in oven it will increase in volume
Put a balloon in freezer it will decrease in volume