Chapter 4, 5 and 6 HW

This diagram shows the approximate depths to which different wavelengths of light penetrate Earth's atmosphere. If we had no atmosphere..

All of these are true.

When you are standing on a scale in an elevator, what exactly does the scale measure?

the force you exert on the scale

Which of the following forms of light can be observed with telescopes at sea level?

visible light radio waves

Imagine being on the Moon and looking at the thermal radiation spectrum of Earth. How would it compare to the spectra shown on the graph in the video?

It would be very similar to the spectrum of the human.

Each of the following diagrams shows a spaceships somewhere along the way between Earth and the Moon (not to scale); the midpoint of the distance is marked to make it easier to see how the locations compare. Rank the five positions of the spaceship from left to right based on the strength of the gravitational force that Earth exerts on the spaceship, from strongest to weakest. (Assume the spaceship has the same mass throughout the trip; that is, it is not burning any fuel.)

closest to earth earth side of midpoint midpoint moon side of midpoint closest to moon

The James Webb Space Telescope is designed primarily to observe __________.

infrared light

Listed following are various physical situations that describe how light interacts with matter. Match these to the appropriate category.

Transmission- visible light meets clear glass, cell phone signals pass through walls Absorption- visible light does not pass through a black wall, blue light hits a red sweatshirt Reflection or scattering- red light hits a red sweatshirt, white light hits a white piece of paper Emission- light comes from your computer screen, light comes from a light bulb

The sum of the number of protons and neutrons in an atom is called the

atomic mass number

The first telescopic photo shows what appears to be a single star. The second photo shows the same object, now revealed to be two distinct stars. What is the difference between the two photos?

The second photo has better (smaller) angular resolution than the first photo.

Each chemical element has a unique

atomic number

The number of protons in an atom is called the atom's

atomic number

Consider Earth and the Moon. As you should now realize, the gravitational force that Earth exerts on the Moon is equal and opposite to that which the Moon exerts on Earth. Therefore, according to Newton's second law of motion _______.

the Moon has a larger acceleration than Earth, because it has a smaller mass

Which of the following statements about the double slit experiment is false?

It produces the same results for marbles and bowling balls as it does for electrons and photons.

Rank the forms of light from left to right in order of increasing energy. To rank items as equivalent, overlap them.

radio waves infrared visible light ultraviolet x rays gamma rays

Rank the forms of light from left to right in order of increasing frequency. To rank items as equivalent, overlap them.

radio waves infrared visible light ultraviolet x rays gamma rays

Compared to a cold object, a hotter object of the same size emits most of its light at __________ wavelengths and emits _____ light overall.

shorter, more

What is the correct composition of a neutral atom of helium-4?

2 protons, 2 neutrons, 2 electrons

Suppose you are in an elevator car when the cable breaks. Which of the following correctly describes what happens and why?

You float weightlessly within the elevator car because you and the elevator both begin to accelerate downward at the same time

Study the graph of the intensity of light versus wavelength for continuous spectra, observing how it changes with the temperature of the light bulb. Recall that one of the laws of thermal radiation states that a higher-temperature object emits photons with higher average energy (Wien's law). This law is illustrated by the fact that for a high temperature object, the graph peaks at _______

a shorter wavelength

Rank the forms of light from left to right in order of increasing speed. To rank items as equivalent, overlap them.

all stacked

What type of visible light spectrum does the Sun produce?

an absorption line spectrum

Which of the following type of spectrum would you expect if you view star light that has passed through a cool cloud of interstellar gas on its way to Earth?

an absorption line spectrum

The following diagrams are the same as those from Part A. Again considering only the two objects shown in each pair, this time rank the strength, from strongest to weakest, of the gravitational force acting on the object on the right.

asteroid---d---Sun asteroid---d---Earth asteroid---d---Moon asteroid---d---asteroid asteroid---d---hydrogen atom

The following five diagrams show pairs of astronomical objects that are all separated by the same distance d. Assume the asteroids are all identical and relatively small, just a few kilometers across. Considering only the two objects shown in each pair, rank the strength, from strongest to weakest, of the gravitational force acting on the asteroid on the left.

asteroid---d---Sun asteroid---d---Earth asteroid---d---Moon asteroid---d---asteroid asteroid---d---hydrogen atom

The absorption line spectrum shows what we see when we look at a hot light source (such as a star or light bulb) directly behind a cooler cloud of gas. Suppose instead that we are looking at the gas cloud but the light source is off to the side instead of directly behind it. In that case, the spectrum would __________.

be an emission line spectrum

An atom with more electrons than protons has a negative

electric charge

Suppose that the Sun were to collapse from its current radius of about 700,000 km to a radius of only about 6000 km (about the radius of Earth). What would you expect to happen as a result?

A tremendous amount of gravitational potential energy would be converted into other forms of energy, and the Sun would spin more rapidly

In Part A, you found that your weight will be greater than normal when the elevator is moving upward with increasing speed. For which of the following other motions would your weight also be greater than your normal weight?

The elevator moves downward while slowing in speed.

Consider a planet orbiting another star that is very similar to our Sun. Assume the planet is about the size of Earth and has an Earth-like orbit around its star. Which of the following statements are true about the light coming from the star and planet?

The planet emits virtually all its light as infrared light. The star emits much more total light than the planet. The star's spectrum peaks in visible light

Most hydrogen atoms have only a single proton in their nucleus, so a hydrogen atom that also has one neutron is an _______ of hydrogen

isotope

Thermal radiation gets its name because __________.

its spectrum depends on the temperature of the object emitting it

Incandescent light bulbs emit thermal radiation because their filaments are heated to about 2500 Kelvin. LED light bulbs emit only at particular visible wavelengths. Why do incandescent bulbs require more energy to shine with the same amount of visible light as LED bulbs?

Incandescent bulbs emit most of their energy as infrared light.

Suppose that two asteroids are orbiting the Sun on nearly identical orbits, and they happen to pass close enough to each other to have their orbits altered by this gravitational encounter. If one of the asteroids ends up moving to an orbit that is closer to the Sun, what happens to the other asteroid?

It will end up on an orbit that is farther from the Sun

Which kind of telescope did Newton invent that allowed for telescopes to be shorter?

a reflecting telescope

The following diagrams are the same as those from Part A. This time, rank the pairs from left to right based on the size of the acceleration the asteroid on the left would have due to the gravitational force exerted on it by the object on the right, from largest to smallest.

asteroid---d---Sun asteroid---d---Earth asteroid---d---Moon asteroid---d---asteroid asteroid---d---hydrogen atom

The following diagrams are the same as those from Part A. This time, rank the five positions of the spaceship from left to right based on the strength of the gravitational force that the Moon exerts on the spaceship, from strongest to weakest.

closest to moon moon side of midpoint midpoint earth side of midpoint closest to earth

If our eyes were sensitive only to X rays, the world would appear __________.

dark because X-ray light does not reach Earth's surface

We divide the electromagnetic spectrum into six major categories of light, listed below. Rank these forms of light from left to right in order of increasing wavelength. To rank items s equivalent, overlap them.

gamma rays x rays ultraviolet visible light infrared radio waves

The video shows a collapsing cloud of interstellar gas, which is held together by the mutual gravitational attraction of all the atoms and molecules that make up the cloud. As the cloud collapses, the overall force of gravity that draws the cloud inward _______ because _______

gradually becomes stronger the strength of gravity follows an inverse square law with distance

Suppose you are in an elevator. As the elevator starts upward, its speed will increase. During this time when the elevator is moving upward with increasing speed, your weight will be _______

greater than your normal weight at rest

If you had only one telescope and wanted to take both visible-light and ultraviolet pictures of stars, where should you locate your telescope?

in space

As the cloud shrinks in size, its central temperature _______ as a result of its _____

increases gravitational potential energy being converted to thermal energy

Suppose you are in an elevator that is moving upward. as the elevator nears the floor at which you will get off, its speed slows down. During this time when the elevator is moving upward with decreasing speed, your weight will be _______

less than your normal weight at rest

Click "show" for the emission line spectrum, then click "choose gases" and study the emission line spectrum for neon. The neon "OPEN" sign appears reddish-orange because __________.

neon atoms emit many more yellow and red photons than blue and violet photons

As the cloud shrinks in size, its rate of rotation _______ because _______

speeds up its total angular momentum is conserved

The following diagrams show five pairs of asteroids, labeled with their relative masses (M) and distances (d) between them. For example, an asteroid with M=2 has twice the mass of one with M=1 and a distance of d=2 is twice as large as a distance of d=1. Rank each pair from left to right based on the strength of the gravitational force attracting the asteroids to each other, from strongest to weakest.

M=2 d=1 M=2 M=1 d=1 M=2 M=1 d=1 M=1 M=1 d=2 M=2 M=1 d=2 M=1