Physics, 02.06.2020 11:58, Lowkeycaleb
Gold in its pure form is too soft to be used for most jewelry. Therefore, the gold is mixed with other metals to produce an alloy. The composition of gold alloys are always calculated by mass, using the karat (kt) as a unit of measure. A karat represents a proportion by mass of one part in twenty-four. The higher the karat value, the higher the proportion of gold in relation to the total metal content. Pure gold is therefore 24 karat, while an 18-karat gold alloy contains (at least) 18 parts (by mass) of gold out of 24 parts total.
In a sample of 18-karat gold, 75 percent of the total mass is pure gold, while the rest is typically 16 percent silver and 9 percent copper. If the density of pure gold is rhogold = 19.3 g/cm^3, while the densitites of silver and copper are respectively rhosilver = 10.5 g/cm^3 and rhocopper = 8.90 g/cm^3.
a) What is the overall density rho18kt of this alloy of 18-karat gold?
Express your answer in grams per cubic centimeter to three significant figures.
Answers: 3
Physics, 21.06.2019 21:30, canyonrico05
One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?
Answers: 3
Physics, 22.06.2019 11:30, azduce
(2) (a) you have a simple circuit that consists of only a battery (δvbat=1.5v) and two resistors with resistance r1=10ω and r2=5ω, connected in series with each other. what is the current running through the battery? (b) you re-arrange your circuit so now r2 is attached in parallel to r1 rather than in series. what is the current running through the battery? (c) you add an additional resistor r3=7ω on the same branch as r2. what is the current running through the battery? (d) what is the power dissipated in r3?
Answers: 3
Physics, 23.06.2019 00:00, cece3467
The horizontal blue line through the middle of the lens is called the optical axis. as the lamp is moved above or below the axis, keeping the horizontal distance to the center of the lens constant, how does the horizontal distance from the lens to the image change?
Answers: 2
Gold in its pure form is too soft to be used for most jewelry. Therefore, the gold is mixed with oth...
Mathematics, 25.01.2022 20:40
Mathematics, 25.01.2022 20:40
Mathematics, 25.01.2022 20:40
History, 25.01.2022 20:40
Mathematics, 25.01.2022 20:40
Business, 25.01.2022 20:40
Mathematics, 25.01.2022 20:40
Social Studies, 25.01.2022 20:40
Mathematics, 25.01.2022 20:40