SCIE 3301

How much current flows through a lamp with a resistance of 60 Ω when the voltage across it is 12 V? (SG 7.4)

0.2 A

What is the resistance of a toaster that draws 12 A when connected to a 120-V circuit? (SG7.4)

10 Ω

If a 120-V line to a socket is limited to 15 A by a safety fuse, will it operate a 1200-W hair dryer? (7)

Yes

The source of electrons in the wires that charge your smartphone is (SG 7.1)

the wires themselves.

Three lamps are connected in parallel across a 6-V battery. What is a true statement about this? (SG 7.3)

Each lamp has 6 V across it, and one branch can fail without stopping current in the others.

Distinguish among amplitude, wavelength, frequency, and period. (SG 8.2)

Amplitude is maximum displacement from the rest position
Wavelength is the distance between corresponding points such as crest-to-crest
Frequency is the number of waves passing a point each second
Period is the time required for a wave to make one complete cycle.

A wave travels across the surface of water. What is primarily transferred from one location to another? (SG 8.1)

Energy

State Newton’s law of universal gravitation in words and in its symbolic equation. (5.1)

Every mass attracts every other mass with a force proportional to their masses and inversely proportional to the square of the distance between them.
$F=G\frac{m_1m_2}{r^2}$

How does the gravitational force change when the distance between two bodies is doubled? (SG 5.1)

The force becomes one-fourth as strong.

What is meant by the term tangential velocity in relation to the Moon’s orbit? (SG 5.2)

Tangential velocity is motion along a tangent (parallel) to a curved path, keeping the Moon in orbit.

Define weightlessness. (SG 5.4)

Weightlessness is the condition of free fall when no support force is felt.

Explain why the Moon does not crash into Earth even though Earth’s gravity pulls on it. (SG 5.2)

The Moon’s tangential velocity keeps it moving sideways as it falls, so it falls around Earth rather than into it.

Imagine a new planet with twice Earth’s mass and the same radius. Predict how your weight would compare there to your weight on Earth. (5.3)

Weight would be twice as great because gravity is proportional to mass of the planet.

Satellites must move at about 8 km/s to stay in orbit. What would happen if their tangential velocity were reduced to nearly zero? Why? (SG 5.2)

Without tangential velocity, the satellite would fall straight into Earth.

A wave's amplitude increases while its wavelength stays the same. What changes? (SG 8.2)

The wave carries more energy while the spacing between crests stays the same.

Does the medium in which a wave travels move with the wave? (SG 8.1)

No

You dip your finger at a steady rate into a puddle of water to make waves. What happens to the wavelength if you dip your finger more frequently? (SG 8.2)

The wavelength shortens

Can sound travel through a vacuum? Why or why not? (SG 8.3)

No, it requires a medium

Which is louder: a sound wave of high amplitude or one of low amplitude? (SG 8.3)

High amplitude

A sound becomes higher pitched but not louder. Which wave property increased? (SG 8.3)

Frequency

You can hear a person speaking even when the person is just around a corner. Which wave behavior best explains this? (SG 8.4)

Diffraction

White light passes through a prism and separates into colors. Why? (SG 8.5)

Different wavelengths of light refract by different amounts.

What determines whether a material is transparent or opaque? (SG 8.5)

If photons/light can pass through the material.

Two identical satellites orbit Earth. Satellite A is closer to Earth than Satellite B. Provide a statement that best compares the gravitational force on them. (SG5.1)

Satellite A experiences a stronger force because it is closer to Earth.

Describes why the Moon remains in orbit around Earth (SG 5.2)

Earth's gravity continually pulls the Moon inward while it moves forward.

An astronaut travels from Earth to the Moon. What happens to the astronaut's mass and weight? (SG 5.3)

Mass stays the same, but weight decreases.

A student stands on a scale in an elevator. The elevator begins accelerating downward. What should the student observe? (SG 5.4)

The scale reading decreases because apparent weight decreases.

A ball rolls off a table and follows a curved path to the floor. Which explanation best describes its motion? (SG 5.5)

Gravity acts downward while the ball continues moving horizontally.

A metal block at 80°C touches a metal block at 20°C. What happens to the thermal energy? (SG 6.1)

Heat moves from the 80°C block to the 20°C block.

A pot of water is heated from below. Warmer water rises while cooler water sinks. Which heat-transfer process is occurring in the water? (SG 6.2)

Convection

A student feels warmth from a campfire without touching the fire or the heated air directly. Which process best explains the transfer? (SG 6.2)

Radiation

On a very hot day, metal railroad rails buckle where there is not enough space between sections. Why? (SG 6.3)

The rails expand as particle motion increases.

Water droplets form on the outside of a cold glass. Which phase change produced the droplets? (SG 6.4)

Gas to liquid

The force of gravity on astronauts inside an orbiting space vehicle is (SG 5.2)

mainly due to Earth below.

Two objects are moved farther apart while their masses stay the same. What should happen to the gravitational force between them? (SG 5.1)

It becomes weaker because gravitational force decreases with distance.

A student says that Earth pulls on a falling ball, but the ball does not pull on Earth. Evaluate the student's claim. (SG 5.1)

The student is incorrect because both Earth and the other ball exert gravitational forces on each other.

Two identical objects are placed at different distances from Earth. Object A is closer to the Earth than Object B. What is an accurate comparison? (SG 5.1)

Object A experiences a stronger gravitational attraction because it is closer to Earth.

An astronaut appears to float inside a spacecraft orbiting Earth. What is an explanation for this? (SG 5.4)

The astronaut and spacecraft are falling around Earth together

A ball is thrown horizontally from a high platform. Why does it follow a curved path toward the ground? (SG 5.5)

Gravity acts downward while the ball continues moving horizontally.

A teacher wants students to investigate projectile motion. What could help students gather evidence about how one variable affects range? (SG 5.5)

Have students launch the same soft ball at different angles while keeping launch speed as consistent as possible & measure the distance traveled.

Circular Earth orbits are characterized by a constant (SG 5.2)

acceleration, speed, radial distance

There is twice as much molecular kinetic energy in 2 liters of boiling water as in 1 liter of boiling water. What do they share (SG 6.1)

Temperature

The same quantity of heat is added to different amounts of water in two equal-sized containers. The temperature of the smaller amount of water (SG 6.1)

increases more

You heat a half cup of tea and its temperature rises by 4C how much will the temperature rise if you add the same amount of heat to a full cup of tea? (SG 6.1)

2C

Due to thermal expansion telephone lines appear to _______ in the summer (SG 6.3)

sag

When a sample of 0C water is heated, it first (SG 6.3)

contracts

Two samples of boiling water are both at 100°C, but one sample contains twice as much water as the other. Which statement is correct? (SG 6.1)

Both have the same temperature, but the larger sample has more total thermal energy.

A sample of 0°-C air at constant pressure lowered by 1 degree has a volume that (SG 6.3)

shrinks by 1/273.

How can energy from the Sun warm Earth even though space between the Sun and Earth is nearly a vacuum? (SG 6.2)

Electromagnetic radiation carries radiant energy through space.

Temperature is a measure of the (SG 6.1)

average translational kinetic energy of molecules.

Because of trapped air inside, snow is a (SG 6.4)

good insulator & poor conductor

Heat is thermal energy that matter (SG 6.1)

transfers

Because of gas that is trapped between the double glass surface of drinking ware (SG 6.4)

conductivity is lessened and insulation is increased

A tile floor and a wooden floor are at the same room temperature, but the tile feels colder to bare feet. Why? (SG 6.4)

Tile conducts thermal energy away from the feet more rapidly than wood.

Why are expansion joints built into long bridges and concrete roadways? (SG 6.3)

To allow materials to expand and contract as temperature changes

Warm air above a heater rises while cooler air moves in to replace it. Which method of heat transfer is illustrated? (SG 6.2)

Convection

A metal ring with a gap takes the shape of the letter C. When the ring is cooled, the gap becomes (SG 6.3)

narrower