Download Physical Science 2nd Semester Study Guide

Physical Science 2nd Semester Study Guide with Answers
Energy and Energy Transformations
1. Explain transfer of heat through Conduction, Convection and Radiation. Include
examples and diagrams. Conduction-direct contact through solids, convection-heat is
transferred through liquids and gases through currents. Radiation – when energy is
transferred by electromagnetic waves through empty space. (See text chapter 15
section 2 for examples & diagrams)
2. Explain how potential can change to kinetic energy and vice versa. Potential energy is
stored energy and when an object begins to move it is converted to kinetic energy.
3. Give examples of kinetic energy anything in motion, ball in motion, airplane flying.
Kinetic E is based on mass and speed.
4. Give examples of potential energy any object that has the ability to have motion but is
not in use yet. Potential E is based height and mass.
5. How do currents of heat travel in a liquid or gas? Convection
6. What form of energy does a vibrating object give off? Sound
7. Describe the energy transformations that occur when lighting a match Mechanical
E.(moving hand), chemical (chemical reaction), thermal (heat), and then radiant
(light from match lighting)
8. The law of conservation of energy states: Energy can’t be created or destroyed but it
only changes forms.
9. Draw and label a diagram illustrating the greatest potential/kinetic energy. Think of a
roller coaster and the greatest potential is at its highest point and the greatest
kinetic is right before it reaches its lowest point.
10. What process does heat transfer in a vacuum? Radiation-it can occur in a vacuum
because a vacuum is where there are no particles of matter and radiation occurs in
waves around matter not through it like in conduction and convection.
11. What are two ways that heat can be transferred by collisions of particles in matter?
Conduction-direct contact through solids, convection-heat is transferred through
liquids and gases through currents
12. Describe what happens when chemical energy is converted into thermal energy. This
happens with a chemical reaction and the amount of energy stays the same it just
changes form-Law of conservation of energy.
13. Compare one glass of water at 0 C degrees and one glass of water at 30 C degrees. Heat
always transfers from hot to cold. There is more thermal energy and kinetic energy
the warmer the water.
14. What can cause convection in liquids and gases? When you heat a liquid from below it
causes currents because heat rises then cools slightly and the process repeats itself.
Forces, Motion & Simple Machines
15. What causes an object to slow down when initially moving? Friction because it opposes
the motion of an object
16. Which simple machine would you use to pry a heavy rock from the ground? Lever-any
bar that has a pivot point (fulcrum) and is used to do work
17. Explain how mass controls acceleration of an object. Acceleration is based on mass and
the amount of force. If the mass of an object is less, then it requires less force.
However, if the mass of 2 metal balls is 15 grams and 2 grams and equal force is
applied then the 2 gram ball will accelerate faster.
18. How does a wheel and axle make work easier? Increases effort force and increases the
distance covered
19. If the threads of a screw where unwrapped what would they represent? Incline plane
20. Which kinds of forces are exerted on an object if there is a net force of zero? Balanced
because each force being exerted is equal to the other. When you subtract all forces
from each other that should equal zero.
21. How do you calculate net force? Subtract
22. Describe 3 ways an object accelerates. An object is considered accelerating when it
speeds up, slows down or changing direction like turning.
23. How does a single fixed pulley make work easier? Changes the direction of the input
force
24. An ice skater is moving in a straight line with constant speed. Which describes the forces
acting on the skater? The forces are balanced because nothing is changing, not the
speed or direction.
25. What can cause a machine to be less than 100 percent efficient?Friction
26. What is the difference between speed and velocity? Velocity has direction
27. How do you calculate work? Work divided by time
28. Explain how a lever works and include examples. A lever is a bar that pivots around a
fixed point called a fulcrum. 1st class – scissors & pliers; 2nd class – wheelbarrow; 3rd
class – baseball bat
29. Explain how momentum is transferred when bowling.When the bowling ball hits the
pins, the ball and the binse bounce off each other. The momentum of the ball and
the pins changes during the collison. The law of conservation of momentum means
that collisions between these objects don’t change the total momentum of all the
objects in the group.
30. Based on Newton’s 1st Law (state), what happens to an object that is moving and is
suddenly stopped? Newton’s first law states that objects in motion tent to stay in
motion and objects at rest tend to stay at rest unless acted upon by an outside force.
If a car is moving and suddenly stops, the car stops but the person inside will still
move forward until the seatbelt stops them. (momentum)
Sound/Light Waves
31. Draw and label a diagram of parts of a transverse and compressional wave. In text p. 467
& 468
32. List types of electromagnetic waves (remember your flipbook) Lowest to Highest
frequency. Remember the Gamma Rays has the strongest energy and the shortest
wavelength and the highest frequency. Radio waves have the opposite on each.
Remember ROYGBIV-red being longest wavelength and violet being the shortest.
Order – Saying “Red Martians Invade Venus Using X-Ray Guns”
33. Describe what happens when refraction occurs. The light wave actually changes speed
as it goes from one medium to another. An example is like when we put the pencil in
the water and the pencil appeared bent or broken.
34. What travels faster? Sound or light, why? Light travels the fastest. Think about this is
why you see the lightning and then hear the thunder.
35. What reflects light? All matter reflects light
36. How do you measure wavelength? Crest to crest, Trough to trough, or from any given
point on a wave to the same point on the next wave. For a sound wave, from the
center point of a compression or rarefaction to the center of the next compression or
rarefaction.
37. Which color is the best to wear when hot? Light colored reflects light and heat.
38. Where can sound not travel? In empty space or a vacuum.
39. Explain the Doppler Effect and include a diagram representing the waves. (see text p.
496) As an object moves closer to you the frequency increases which creates a higher
pitch, and as it moves away from you the frequency decreases which creates a lower
pitch.
40. Explain how sound waves transfer. Where do they travel the fastest, slowest? Sound
travels by vibrating particles. It travels fastest in a solid and slowest in a gas.
41. What would make a pitch of a sound wave lower? By decreasing the frequency or
increasing the length of a wave. A pitch can also be lowered with a string instrument
by increasing the thickness of the string or decease the tension of the string.
42. What type of image does a flat mirror produce? A regular, because light is reflecting
back at the same angle
43. What part of the eye is responsible for controlling the amount of light that enters? The
pupil opens more when more light is needed and constricts when less light is to see
44. What happens to the particles in a medium when sounds pass through it? They vibrate
45. How is wave speed calculated? Wavelength x frequency
46. What would you measure to determine a wave’s frequency? The number of waves that
pass a given point in a second
47. A lightning flash produces thunder at the same time the lightning flash occurs. What is
the best way to explain why we see the lightning before we hear the thunder? Light
waves travel faster than sound waves.
48. Explain how light travels through matter and what happens when no matter is present,
vacuum. In a vacuum where no particles are present because light has to travel
around matter so it travels faster.
49. What describes why a certain flower has a red color? Red light is being reflected and all
other colors are being absorbed.
50. Draw and label: concave lens, convex lens, concave mirror, convex mirror-how does
light behave with each? Remember a difference between a lens and a mirror is the
lens allows light waves to pass through it. Concave is angled like a cave when you
are walking into it. The image flipped and with convex the angle becomes larger at
the edges.
51. What do waves carry as they move from one place to another? Waves carry energy as
they move.
52. What is frequency measured in? The unit of measurement for frequency is hertz.
53. Describe all factors involved with the amplitude of a sound wave. Amplitude represents
the energy of a wave, the height of a wave and the sound intensity of a sound wave.
54. Why does refraction of a wave occur when the wave travels from one material into
another? The wave speed changes because density of the particles is different from
one particle to another. With sound waves the wave speed increases when the
particles are closer together and with light, the wave speed slows down because the
particles are close together.
55. What EM waves do all warm bodies emit? Heat as infrared waves
56. Explain how light behaves with each: transmitting, reflecting, refracting, diffracting.
Transmitting means the light wave passes through a medium; reflecting means the
light wave will bounce back at you after hitting a barrier; refracting is the bending
of light wave as it passes at an angle from one medium to another, and diffracting is
the bending, spreading or interference of light waves when they go through a
narrow opening.
57. Compare transparent, translucent and opaque transfer of light. Transparent means the
light is allowed to pass through a material, translucent means that some light will
pass through the material but also scatter the light in all directions. Opaque means
light will not be allowed to pass through the material.
Electricity
58. Describe how electric charges exert forces on each other? Like charges will repel and
unlike charges will attract. The electric force between two charged objects gets
stronger as the charges get closer. Also, the amount of charge on each will have an
effect on the force.
59. In a series circuit, what is the same for every device in the circuit? The flow of
electricity
60. What happens in a series circuit if one of the light bulbs is unscrewed? None of the light
bulbs will be lit.
61. What device helps make an electromagnet work?
Discussion –Know enough to write a paragraph for each. Diagrams with labels should
be included.
1. Why do we see the color of red when looking at an apple?
2. Jesse and Heather were wading at the shoreline. They both realized that the shapes of the
objects they saw on the bottom appeared distorted. Why would the objects appear this
way?
3. Explain the advantages and disadvantages of series and parallel circuits in terms of how
much energy flows to each bulb, whether lights stay lighted when a circuit fails and draw
a picture and label each.
4. The advantage of a simple machine is that it makes doing a job easier. Describe and give
an example of the three ways that simple machines can make doing a job easier.
5. State the law of conservation of energy and explain how it is applied through an example
during its transformation.
6. Explain the 3 ways to make an electromagnet stronger.