Science Standards Review: Energy. S8P2. Students will be familiar with the forms and transformations of energy. . a. Explain energy transformation in terms of the Law of Conservation of Energy. . The law of conservation of energy states that: . Energy is never destroyed
S8P2. Students will be familiar with the forms and transformations of energy.
a. Explain energy transformation in terms of the Law of Conservation of Energy.
c. Compare and contrast the different forms of energy (heat, light, electricity, mechanical motion, sound) and their characteristics.
Heat(thermal)—the vibration and movement of the atoms and molecules within substances
ex. Atoms move faster in hot water vs. ice water
Light (radiant)—is electromagnetic energy
ex. Sunlight, X-rays,
Electricity—energy of moving electrons, typically moving through a wire
Mechanical Motion—is energy stored in a moving object or an object that can move
PE + KE = mechanical energy
ex. Wind, Jack in the Box
Chemical—energy stored in the bonds of atoms and molecules (is released during chemical changes when atoms are rearranged)
ex. Cells in our body store chemical energy
Nuclear—energy stored in the nucleus of an atom — the energy that
holds the nucleus together
ex. Nuclear power plants
d. Describe how heat can be transferred through matter by the collisions of atoms (conduction) or through space (radiation). In a liquid or gas, currents will facilitate the transfer of heat (convection).
Conduction is the transfer of energy through matter from particle to particle as they touch.
the transfer of thermal energy by the movement of a gas or liquid (a medium).
The circular motion caused by density differences that result from temperature differences are called convection currents.
Energy from the sun
Microwaves use radiation
Which of the following converts electrical
energy into mechanical?
A light switch B electric stove
C light bulb D electric fan
According to the Law of Conservation of Energy, if Sally throws a watermelon with 100 joules of energy off the roof of a building, how much energy should the watermelon have as it hits the ground?
When a rock is thrown straight up into the air, it reaches its highest point and briefly comes to a complete stop before it starts to fall back to the ground. Which is greatest at the point where the rock stops?
A house becomes warm after air circulates in the house. What type of heat transfer happens?
A B C D
Where is potential energy the greatest?
A B C D
Tonya drops a ball off a cliff as shown in the picture. Which position shows where the ball has the most kinetic energy and the least potential energy?
Bob sat by the pool too long and his skin began to burn. What type of heat transfer occurred to make him burn?
a. A b. B
c. C d. D
At which position in the pendulum swing is potential energy the lowest?
a. A b. B
c. C d. D
A. Heat to electrical
B. Chemical to mechanical
C. Mechanical to light
D. Heat to mechanical
What type of heat transfer is happening in the air around the candle?
A gasoline-powered vehicle goes up a hill from point X to point Y. What energy transformation must occur in the car’s engine?
A Chemical energy into mechanical energy
B Electrical energy into light energy
C Electrical energy into sound energy
D Mechanical energy into light energy
When walking along an asphalt street after sundown, a person often feels heat coming off the pavement. The heat is moving from the asphalt to the person by
Heat, light, and electricity are all forms of
In the pictures below, the candle is heating the water in the tank. Which picture shows how the water will move as it gets hot?
My dog, Ralph, wears slippers on hot days because the pavement is hot on his feet. What type of heat transfer makes his feet hot?
S8P3. Students will investigate relationship between force, mass, and the motion of objects.
a. Determine the relationship between velocity and acceleration.
Tom is traveling west at 50 miles per hour. Sally and her family are traveling south at 50 miles per hour. Do the cars have the same velocity? Why or why not?
b. Demonstrate the effect of balanced and unbalanced forces on an object in terms of gravity, inertia, and friction.
Decide whether the following pictures represent a balanced or unbalanced force
Yes, you really are attracted to your science book!
a. Recognize that every object exerts gravitational force on every other object and that the force exerted depends on how much mass the objects have and how far apart they are.
More mass more inertia
Less mass less inertia
c. Demonstrate the effect of simple machines (lever, inclined plane, pulley, wedge, screw, and wheel and axle) on work.
The closer the threads the greater the mechanical advantage
3 different classes (types) of levers
Examples: Seesaw, scissors, pliers, catapult
Input force (effort)
1st Class– fulcrum in the middle
2nd Class– load is in the middle
3rd Class– Effort (input force) is in the middle
Input force (effort)
Example: flag pole, sail boat, elevators
Which characteristic of motion could change without changing the velocity of an object?
A the speed B the position
C the direction D the acceleration
What two forces are responsible for keeping Earth in orbit around the sun?
Which of the following represents the velocity of a moving object?
If the spring is pulled 3.5 cm, the spring scale should read
A 12 N. B 13 N.
C 14 N. D 15 N.
A ball is dropped from the top of a tall building. As the ball falls, the upward force of air resistance becomes equal to the downward pull of gravity. When these two forces become equal in magnitude, the ball will
A flatten due to the forces.
B fall at a constant speed.
C continue to speed up.
D slow to a stop.
A 50 N. B 150 N.
C 200 N. D 350 N.
A downward and to the left.
B downward and to the right.
C upward and to the left.
D upward and to the right.
When you bend your arm at the elbow, the bones and muscles in your arm are acting as a system. What simple machine does this system represent?
Which simple machine is a pair of scissors?
On Earth, an astronaut has a mass of 140 kg. When the astronaut goes into space, she
A person dives out of a nonmoving boat in the direction indicated by Arrow A. Which arrow shows the direction in which the boat would move?
The tendency for a body at rest to remain at rest is known as
Where should Melissa position the fulcrum in order to minimize the amount of force needed to lift the box?
S8P4. Students will explore the wave nature of sound and electromagnetic radiation.
a. Identify the characteristics of electromagnetic and mechanical waves.
b. Describe how the behavior of light waves is manipulated causing reflection, refraction diffraction, and absorption.
c. Explain how the human eye sees objects and colors in terms of wavelengths.
d. Describe how the behavior of waves is affected by medium (such as air, water, solids).
Warmer objects will conduct sound faster
Particles move faster in warm object so they transfer the sound faster
f. Diagram the parts of the wave and explain how the parts are affected by changes in amplitude and pitch.
Crest—the highest point of a transverse wave
Trough—the lowest point of a transverse wave
Wavelength—the distance from any point on one wave to an identical point on the next wave
Amplitude—the maximum distance that the particles of a wave vibrate from their rest position
This wave will sound loud
The frequency of a wave determines pitch.
A wave with a high frequency has a high pitch.
A wave with a low frequency has a low pitch.
This wave would have a low pitch.
When Marcia yelled from the top of a canyon, an echo was created. This happened because the sound waves of her voice bounced back from the canyon walls. Which property of waves occurred?
There is only one fish in the fishbowl below. When Joseph looks down at the fish, the image he observes is closer to the surface than the actual location of the fish.
Which wave characteristic does Joseph’s observation demonstrate?
A. amplitude B. diffraction
C. reflection D. refraction
Why are light-colored clothes cooler to wear in the summer than dark-colored clothes?
A family is building an outdoor shower at their cottage by hanging a plastic container from a post, as shown above. The container will be exposed to full sunlight. What color should the container be to make the water as warm as possible?
In old movies, people sometimes put their ear on a railroad track to see if a train is coming. This works because the iron rail
Sound A has a shorter wavelength than Sound B. This means that Sound A will
Which wave has the highest frequency?
Which wave has the highest pitch?
Which wave has the softest sound?
Which wave has the loudest sound?
S8P5. Students will recognize characteristics of gravity, electricity, and magnetism as major kinds of forces acting in nature.
b. Demonstrate the advantages and disadvantages of series and parallel circuits and how they transfer energy.
c. Investigate and explain that electric currents and magnets can exert force on each other.
At which location is Earth’s magnetic field the strongest?
1 B. 2
C. 3 D. 4
A Electricity flows along one pathway.
B The flow of electricity comes from one source.
C Electricity flows along more than one pathway.
D The flow of electricity comes from more than one source
Three identical light bulbs are connected in parallel with a battery, as shown, and all are lit. If bulb I is unscrewed and removed, what will happen to the other two light bulbs?