Concept explainers
(a)
The fraction of the galaxy’s volume is occupied by stars.
(a)
Answer to Problem 34PQ
The fraction of the galaxy’s volume is occupied by stars is
Explanation of Solution
Write the equation of fraction of galaxy’s volume is occupied by stars.
Here,
Write the expression for the volume of star.
Here,
Rewrite the expression for the fraction.
Conclusion:
Substitute
Thus, the fraction of the galaxy’s volume is occupied by stars is
(b)
The mean free path of a star through galaxy.
(b)
Answer to Problem 34PQ
The mean free path of a star through galaxy is
Explanation of Solution
Write the equation of mean free path.
Here,
Conclusion:
Substitute,
Thus, the mean free path of a star through galaxy is
(c)
The probability of collision.
(c)
Answer to Problem 34PQ
The probability of collision is
Explanation of Solution
Write the equation for the probability.
Here,
Conclusion:
Substitute
Therefore, the probability of collision is
Want to see more full solutions like this?
Chapter 20 Solutions
EBK PHYSICS FOR SCIENTISTS AND ENGINEER
- 2. Consider the situation described in problem 1 where light emerges horizontally from ground level. Take k = 0.0020 m' and no = 1.0001 and find at which horizontal distance, x, the ray reaches a height of y = 1.5 m.arrow_forward2-3. Consider the situation of the reflection of a pulse at the interface of two string described in the previous problem. In addition to the net disturbances being equal at the junction, the slope of the net disturbances must also be equal at the junction at all times. Given that p1 = 4.0 g/m, H2 = 9.0 g/m and Aj = 0.50 cm find 2. A, (Answer: -0.10 cm) and 3. Ay. (Answer: 0.40 cm)please I need to show all work step by step problems 2 and 3arrow_forwardFrom number 2 and 3 I just want to show all problems step by step please do not short cut look for formulaarrow_forward
- Look at the answer and please show all work step by steparrow_forward3. As a woman, who's eyes are h = 1.5 m above the ground, looks down the road sees a tree with height H = 9.0 m. Below the tree is what appears to be a reflection of the tree. The observation of this apparent reflection gives the illusion of water on the roadway. This effect is commonly called a mirage. Use the results of questions 1 and 2 and the principle of ray reversibility to analyze the diagram below. Assume that light leaving the top of the tree bends toward the horizontal until it just grazes ground level. After that, the ray bends upward eventually reaching the woman's eyes. The woman interprets this incoming light as if it came from an image of the tree. Determine the size, H', of the image. (Answer 8.8 m) please show all work step by steparrow_forwardNo chatgpt pls will upvotearrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning