Astronomy
1st Edition
ISBN: 9781938168284
Author: Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher: OpenStax
expand_more
expand_more
format_list_bulleted
Concept explainers
Textbook Question
Chapter 21, Problem 2E
Why is star formation more likely to occur in cold molecular clouds than in regions where the temperature of the interstellar medium is several hundred thousand degrees?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
An object is subjected to a friction force with magnitude 5.49 N, which acts against the object's velocity. What is the work (in J) needed to move the object at constant speed for the following routes?
y (m)
C
B
(5.00, 5.00)
A
x (m)
©
(a) the purple path O to A followed by a return purple path to O
]
(b) the purple path O to C followed by a return blue path to O
]
(c) the blue path O to C followed by a return blue path to O
]
(d) Each of your three answers should be nonzero. What is the significance of this observation?
○ The force of friction is a conservative force.
○ The force of friction is a nonconservative force.
A block of mass m = 2.50 kg is pushed d = 2.30 m along a frictionless horizontal table by a constant applied force of magnitude F = 10.0 N directed at an angle
25.0° below the horizontal as shown in the figure below.
m
(a) Determine the work done by the applied force.
]
(b) Determine the work done by the normal force exerted by the table.
]
(c) Determine the work done by the force of gravity.
]
(d) Determine the work done by the net force on the block.
]
A man pushing a crate of mass m = 92.0 kg at a speed of v = 0.845 m/s encounters a rough horizontal surface of length = 0.65 m as in the figure below. If the coefficient of kinetic friction between the crate and rough surface is 0.357 and he exerts a constant horizontal force of 294 N on
the crate.
e
(a) Find the magnitude and direction of the net force on the crate while it is on the rough surface.
magnitude
direction
---Select---
N
(b) Find the net work done on the crate while it is on the rough surface.
]
(c) Find the speed of the crate when it reaches the end of the rough surface.
m/s
Chapter 21 Solutions
Astronomy
Ch. 21 - Give several reasons the Orion molecular cloud is...Ch. 21 - Why is star formation more likely to occur in cold...Ch. 21 - Why have we learned a lot about star formation...Ch. 21 - Describe what happens when a star forms. Begin...Ch. 21 - Describe how the T Tauri star stage in the life of...Ch. 21 - Look at the four stages shown in Figure 21.8. In...Ch. 21 - The evolutionary track for a star of 1 solar mass...Ch. 21 - Two protostars, one 10 times the mass of the Sun...Ch. 21 - Compare the scale (size) of a typical dusty disk...Ch. 21 - Why is it so hard to see planets around other...
Ch. 21 - Why did it take astronomers until 1995 to discover...Ch. 21 - Which types of planets are most easily detected by...Ch. 21 - List three ways in which the exoplanets we have...Ch. 21 - List any similarities between discovered...Ch. 21 - What revisions to the theory of planet formation...Ch. 21 - Why are young Jupiters easier to see with direct...Ch. 21 - A friend of yours who did not do well in her...Ch. 21 - Observations suggest that it takes more than 3...Ch. 21 - Suppose you wanted to observe a planet around...Ch. 21 - Why were giant planets close to their stars the...Ch. 21 - Exoplanets in eccentric orbits experience large...Ch. 21 - When astronomers found the first giant planets...Ch. 21 - An exoplanetary system has two known planets....Ch. 21 - Kepler’s third law says that the orbital period...Ch. 21 - Calculate the transit depth for an M dwarf star...Ch. 21 - If a transit depth of 0.00001 can be detected with...Ch. 21 - What fraction of gas giant planets seems to have...
Additional Science Textbook Solutions
Find more solutions based on key concepts
22. If you bake a cake at high elevation, where atmospheric pressure is lower than at sea level, you will need ...
College Physics: A Strategic Approach (3rd Edition)
2. Define equilibrium population. Outline the conditions that must be met for a population to stay in genetic e...
Biology: Life on Earth (11th Edition)
Acetobacter is necessary for only one of the steps of vitamin C manufacture. The easiest way to accomplish this...
Microbiology: An Introduction
Chlorine has two isotopes, 35Cl and 37Cl; 75.77% of chlorine is 35Cl, and 24.23% is 37Cl. The atomic mass of 35...
Organic Chemistry (8th Edition)
What are the two types of bone marrow, and what are their functions?
Human Anatomy & Physiology (2nd Edition)
WHAT IF What would the discovery of a bacterial species that is a methanogen imply about the evolution of the ...
Campbell Biology (11th Edition)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- Two blocks, A and B (with mass 45 kg and 120 kg, respectively), are connected by a string, as shown in the figure below. The pulley is frictionless and of negligible mass. The coefficient of kinetic friction between block A and the incline is μk = 0.26. Determine the change in the kinetic energy of block A as it moves from to, a distance of 15 m up the incline (and block B drops downward a distance of 15 m) if the system starts from rest. × J 37° Barrow_forwardYou are working for the Highway Department. In mountainous regions, highways sometimes include a runaway truck ramp, and you are asked to help with the design of such a ramp. A runaway truck ramp is often a lane of gravel adjacent to a long downhill section of roadway where trucks with failing brakes may need assistance to stop. Working with your supervisor, you develop a worst-case scenario: a truck with a mass of 6.00 × 104 kg enters a runaway truck lane traveling at 34.1 m/s. Assume that the maximum constant value for safe acceleration of the truck is -5.00 m/s². Any higher magnitude of acceleration increases the likelihood that semi-trailer rigs could jackknife. Your supervisor asks you to advise her on the required length (in m) of a runaway truck lane on a flat section of ground next to the roadway. marrow_forwardA large cruise ship of mass 6.20 × 107 kg has a speed of 10.2 m/s at some instant. (a) What is the ship's kinetic energy at this time? ] (b) How much work is required to stop it? (Give the work done on the ship. Include the sign of the value in your answer.) ] (c) What is the magnitude of the constant force required to stop it as it undergoes a displacement of 3.10 km? Narrow_forward
- A 7.80 g bullet is initially moving at 660 m/s just before it penetrates a block of wood to a depth of 6.20 cm. (a) What is the magnitude of the average frictional force (in N) that is exerted on the bullet while it is moving through the block of wood? Use work and energy considerations to obtain your answer. N (b) Assuming the frictional force is constant, how much time (in s) elapses between the moment the bullet enters the block of wood and the moment it stops moving? Sarrow_forwardPlease don't use Chatgpt will upvote and give handwritten solutionarrow_forwardTwo blocks, A and B (with mass 45 kg and 120 kg, respectively), are connected by a string, as shown in the figure below. The pulley is frictionless and of negligible mass. The coefficient of kinetic friction between block A and the incline is μk = 0.26. Determine the change in the kinetic energy of block A as it moves from to ①, a distance of 15 m up the incline (and block B drops downward a distance of 15 m) if the system starts from rest. ] 37° A © Barrow_forward
- A skateboarder with his board can be modeled as a particle of mass 80.0 kg, located at his center of mass. As shown in the figure below, the skateboarder starts from rest in a crouching position at one lip of a half-pipe (point). On his descent, the skateboarder moves without friction so that his center of mass moves through one quarter of a circle of radius 6.20 m. i (a) Find his speed at the bottom of the half-pipe (point Ⓡ). m/s (b) Immediately after passing point Ⓑ, he stands up and raises his arms, lifting his center of mass and essentially "pumping" energy into the system. Next, the skateboarder glides upward with his center of mass moving in a quarter circle of radius 5.71 m, reaching point D. As he passes through point ①, the speed of the skateboarder is 5.37 m/s. How much chemical potential energy in the body of the skateboarder was converted to mechanical energy when he stood up at point Ⓑ? ] (c) How high above point ① does he rise? marrow_forwardA 31.0-kg child on a 3.00-m-long swing is released from rest when the ropes of the swing make an angle of 29.0° with the vertical. (a) Neglecting friction, find the child's speed at the lowest position. m/s (b) If the actual speed of the child at the lowest position is 2.40 m/s, what is the mechanical energy lost due to friction? ]arrow_forwardA force acting on a particle moving in the xy plane is given by F = (2yî + x²), where F is in newtons and x and y are in meters. The particle moves from the origin to a final position having coordinates x = 5.60 m and y = 5.60 m, as shown in the figure below. y (m) B (x, y) x (m) (a) Calculate the work done by F on the particle as it moves along the purple path (0 Ⓐ©). ] (b) Calculate the work done by ♬ on the particle as it moves along the red path (0 BC). J (c) Is F conservative or nonconservative? ○ conservative nonconservativearrow_forward
- A 3.5-kg block is pushed 2.9 m up a vertical wall with constant speed by a constant force of magnitude F applied at an angle of 0 = 30° with the horizontal, as shown in the figure below. If the coefficient of kinetic friction between block and wall is 0.30, determine the following. (a) the work done by F J (b) the work done by the force of gravity ] (c) the work done by the normal force between block and wall J (d) By how much does the gravitational potential energy increase during the block's motion? ]arrow_forwardPhysics different from a sea breeze from a land breezearrow_forwardFile Preview Design a capacitor for a special purpose. After graduating from medical school you and a friend take a three hour cruise to celebrate and end up stranded on an island. While looking for food, a spider falls on your friend giving them a heart attack. Recalling your physics, you realize you can build a make-shift defibrillator by constructing a capacitor from materials on the boat and charging it using the boat's battery. You know that the capacitor must hold 100 J of energy and be at 1000 V (fortunately this is an electric boat which has batteries that are 1000 V) to work. You decide to construct the capacitor by tightly sandwiching a single layer of Saran wrap between sheets of aluminum foil. You read the Saran wrap box and fortunately they tell you that it has a thickness 0.01 mm and dielectric constant of 2.3. The Saran wrap and foil are 40 cm wide and very long. How long is the final capacitor you build that saves your friend?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Stars and Galaxies (MindTap Course List)PhysicsISBN:9781337399944Author:Michael A. SeedsPublisher:Cengage Learning
AstronomyPhysicsISBN:9781938168284Author:Andrew Fraknoi; David Morrison; Sidney C. WolffPublisher:OpenStax
Foundations of Astronomy (MindTap Course List)PhysicsISBN:9781337399920Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Stars and GalaxiesPhysicsISBN:9781305120785Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Horizons: Exploring the Universe (MindTap Course ...PhysicsISBN:9781305960961Author:Michael A. Seeds, Dana BackmanPublisher:Cengage Learning
Stars and Galaxies (MindTap Course List)
Physics
ISBN:9781337399944
Author:Michael A. Seeds
Publisher:Cengage Learning
Astronomy
Physics
ISBN:9781938168284
Author:Andrew Fraknoi; David Morrison; Sidney C. Wolff
Publisher:OpenStax
Foundations of Astronomy (MindTap Course List)
Physics
ISBN:9781337399920
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
Stars and Galaxies
Physics
ISBN:9781305120785
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning
Horizons: Exploring the Universe (MindTap Course ...
Physics
ISBN:9781305960961
Author:Michael A. Seeds, Dana Backman
Publisher:Cengage Learning