
Concept explainers
Given the abundance of aluminum in the Earth’s crust, explain why it is more expensive than steel.

Given the abundance of aluminum in the Earth’s crust, explain why it is more expensive than steel
Explanation of Solution
Aluminum, being an abundant metallic element, makes up about 8% of the Earth’s crust.
Bauxite serves as the principal ore for aluminum, and is a hydrous (water-containing) aluminum oxide containing various other oxides.
At first, clay and dirt is washed off from the ore. Then the ore is crushed into powder and treated with hot caustic soda (sodium hydroxide) to remove the remaining impurities. Next, extraction of alumina (aluminum oxide) takes place from this solution which is dissolved in a molten sodium-fluoride and aluminum-fluoride bath at a temperature of about 940◦ to 980◦C (1725◦ to 1800◦F).
Then, direct-current electrolysis of this mixture is performed. Aluminum metal is formed at the cathode (negative pole), and oxygen is gathered at the anode (positive pole). Commercially, 99.99% pure aluminum can be obtained. Aluminum production consumes a lot of electricity which affects its cost in comparison to steel.
Want to see more full solutions like this?
Chapter 6 Solutions
Manufacturing Engineering & Technology
- Using the Bernoulli equation to find the general solution. If an initial condition is given, find the particular solution. y' + xy = xy¯¹, y(0) = 3arrow_forwardTest for exactness. If exact, solve. If not, use an integrating factor as given or obtained by inspection or by the theorems in the text. a. 2xydx+x²dy = 0 b. (x2+y2)dx-2xydy = 0 c. 6xydx+5(y + x2)dy = 0arrow_forwardNewton's law of cooling. A thermometer, reading 5°C, is brought into a room whose temperature is 22°C. One minute later the thermometer reading is 12°C. How long does it take until the reading is practically 22°C, say, 21.9°C?arrow_forward
- Solve a. y' + 2xy = ex-x² b. y' + y sin x = ecosx, y(0) = −1 y(0) = −2.5arrow_forward= MMB 241 Tutorial 3.pdf 2/6 90% + + 5. The boat is traveling along the circular path with a speed of v = (0.0625t²) m/s, where t is in seconds. Determine the magnitude of its acceleration when t = 10 s. 40 m v = 0.0625² 6. If the motorcycle has a deceleration of at = (0.001s) m/s² and its speed at position A is 25 m/s, determine the magnitude of its acceleration when it passes point B. .A 90° 300 m n B 2arrow_forward= MMB 241 Tutorial 3.pdf 4/6 67% + 9. The car is traveling along the road with a speed of v = (2 s) m/s, where s is in meters. Determine the magnitude of its acceleration when s = 10 m. v = (2s) m/s 50 m 10. The platform is rotating about the vertical axis such that at any instant its angular position is u = (4t 3/2) rad, where t is in seconds. A ball rolls outward along the radial groove so that its position is r = (0.1+³) m, where t is in seconds. Determine the magnitudes of the velocity and acceleration of the ball when t = 1.5s.arrow_forward
- The population of a certain country is known to increase at a rate proportional to the number of people presently living in the country. If after two years the population has doubled, and after three years the population is 20,000, estimate the number of people initially living in the country.arrow_forward= MMB 241 Tutorial 3.pdf 6/6 100% + | 日 13. The slotted link is pinned at O, and as a result of the constant angular velocity *= 3 rad/s it drives the peg P for a short distance along the spiral guide r = (0.40) m, where 0 is in radians. Determine the radial and transverse components of the velocity and acceleration of P at the instant = 1/3 rad. 0.5 m P r = 0.40 =3 rad/sarrow_forward= MMB 241 Tutorial 3.pdf 1/6 90% + DYNAMICS OF PARTICLES (MMB 241) Tutorial 3 Topic: Kinematics of Particles:- Path and Polar coordinate systems and general curvilinear QUESTIONS motion. 1. Determine the acceleration at s = 2 m if v = (2 s) m/s², where s is in meters. At s = 0, v = 1 m/s. 3 m 2. Determine the acceleration when t=1s if v = (4t2+2) m/s, where t is in seconds. v=(4²+2) m/s 6 marrow_forward
- 5.112 A mounting bracket for electronic components is formed from sheet metal with a uniform thickness. Locate the center of gravity of the bracket. 0.75 in. 3 in. ༧ Fig. P5.112 1.25 in. 0.75 in. y r = 0.625 in. 2.5 in. 1 in. 6 in. xarrow_forward4-105. Replace the force system acting on the beam by an equivalent resultant force and couple moment at point B. A 30 in. 4 in. 12 in. 16 in. B 30% 3 in. 10 in. 250 lb 260 lb 13 5 12 300 lbarrow_forwardSketch and Describe a hatch coaming and show how the hatch coamings are framed in to ships strucure?arrow_forward
- Welding: Principles and Applications (MindTap Cou...Mechanical EngineeringISBN:9781305494695Author:Larry JeffusPublisher:Cengage Learning
