
Concept explainers
(a)
The escape velocity for an object on Earth.
(a)

Answer to Problem 112P
The escape velocity is
Explanation of Solution
Write the expression for conservation of energy
Here,
Write the expression for kinetic energy of a particle
Here,
Write the expression for gravitational potential
Here,
At infinite distance both kinetic and potential energies are considered zero.
Substitute
Rearrange for
Substitute
Thus, the escape velocity of an object is
(b)
The average speed of hydrogen atom at
(b)

Answer to Problem 112P
The average speed of hydrogen atom is
Explanation of Solution
Write the expression for average speed of an atom
Here,
Substitute
Thus, the average speed of hydrogen is
(c)
The average speed of oxygen molecule at
(c)

Answer to Problem 112P
The average speed of oxygen molecule is
Explanation of Solution
Substitute
Thus, the average speed of oxygen molecule is
(d)
The reason for more oxygen than hydrogen on the Earth’s atmosphere.
(d)

Answer to Problem 112P
The average speed of hydrogen is greater for hydrogen.
Explanation of Solution
Particles with velocity lesser than that of the escape velocity cannot escape Earth’s atmosphere.
From the above results, the escape velocity is about six times the average speed of the hydrogen atom. Thus, a small fraction of hydrogen atoms might possess velocity greater than the required escape velocity to cross the Earth’s atmosphere.
The average speed of oxygen molecules is lesser than that of hydrogen and hence only a smaller fraction will possess the required speed to escape Earth’s gravitational pull. Thus, oxygen is found more than hydrogen in the Earth’s atmosphere.
Want to see more full solutions like this?
Chapter 13 Solutions
Physics
- Part A: kg (a) Water at 20 °C (p = 998.3 and v = 1 × 10-6 m²/s) flows through a galvanised m³ iron pipe (k = 0.15 mm) with a diameter of 25 mm, entering the room at point A and discharging at point C from the fully opened gate valve B at a volumetric flow rate of 0.003 m³/s. Determine the required pressure at A, considering all the losses that occur in the system described in Figure Q1. Loss coefficients for pipe fittings have been provided in Table 1. [25 marks] (b) Due to corrosion within the pipe, the average flow velocity at C is observed to be V2 m/s after 10 years of operation whilst the pressure at A remains the same as determined in (a). Determine the average annual rate of growth of k within the pipe. [15 marks] 4₁ Figure Q1. Pipe system Page 2 25 mmarrow_forwardFor an independent study project, you design an experiment to measure the speed of light. You propose to bounce laser light off a mirror that is 53.5 km due east and have it detected by a light sensor that is 119 m due south of the laser. The first problem is to orient the mirror so that the laser light reflects off the mirror and into the light sensor. (a) Determine the angle that the normal to the mirror should make with respect to due west.(b) Since you can read your protractor only so accurately, the mirror is slightly misaligned and the actual angle between the normal to the mirror and due west exceeds the desired amount by 0.003°. Determine how far south you need to move the light sensor in order to detect the reflected laser light.arrow_forwardA mirror hangs 1.67 m above the floor on a vertical wall. A ray of sunlight, reflected off the mirror, forms a spot on the floor 1.41 m from the wall. Later in the day, the spot has moved to a point 2.50 m from the wall. (a) What is the change in the angle of elevation of the Sun, between the two observations?arrow_forward
- It is not (theta 1i) or (pi/2 - theta 2i)arrow_forwardAssume the helium-neon lasers commonly used in student physics laboratories have power outputs of 0.250 mW. (a) If such a laser beam is projected onto a circular spot 3.40 mm in diameter, what is its intensity (in watts per meter squared)? 27.5 W/m² (b) Find the peak magnetic field strength (in teslas). 8.57e-7 X T (c) Find the peak electric field strength (in volts per meter). 144 V/marrow_forwardIdentify the most likely substancearrow_forward
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningUniversity Physics (14th Edition)PhysicsISBN:9780133969290Author:Hugh D. Young, Roger A. FreedmanPublisher:PEARSONIntroduction To Quantum MechanicsPhysicsISBN:9781107189638Author:Griffiths, David J., Schroeter, Darrell F.Publisher:Cambridge University Press
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningLecture- Tutorials for Introductory AstronomyPhysicsISBN:9780321820464Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina BrissendenPublisher:Addison-WesleyCollege Physics: A Strategic Approach (4th Editio...PhysicsISBN:9780134609034Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart FieldPublisher:PEARSON





