Answer:
43.89 min
Explanation:
Given that:-
The speed of light = 
The distance = 
The conversion of distance in km to distance into m is shown below as:-
1 km = 1000 m
So,
Distance = 
The relation between speed distance and time is shown below as:-

Thus,


Time = 2633.33 seconds
Also, 1 s = 1/60 min
So,
Time=
Answer:
3,200 joules
Explanation:
q = mcΔT = (250.0 g)(0.128 j/g°C)(100°C -25°C) = 3,200 joules
Answer:
A. It would float with about 80% of the cube below the surface of the water and 20% above the surface.
Explanation:
The choice that best describes what happens to cube of the given density value is that it would float with about 80% of the cube would be below the surface of the water and 20% above the surface.
Density is the mass per unit volume of a substance. The more mass a body has relative to volume, the great it's density. In short, density is directly proportional to mass and inversely related to volume.
The density of water is 1g/mL
If the density of the cube were to be the same with that of water, the substance will just mix up with water .
Here the density is less than that of water.
The density is 0.2g/mL
Therefore, 20% will stay afloat and 80% will be below the surface of the water.
Answer:
Mass: 981.0 g
Density: 5.61 g/cm^3
Hardness: = 2.5 - 3
Unknown material: Chalcocite
To plot the calibration curve, you need to prepare iron solutions with known concentrations and measure their absorbance. You need to pipet 0 mL of the diluted solution to have 0.00 mg of iron.
In spectrophotometry, to plot the calibration curve, you need to prepare solutions with known concentrations and measure their absorbance.
We have a standard iron solution with a concentration of 0.2500g/L of pure iron (C₁). We pipet 25.00mL (V₁) of this standard iron solution into a 500mL (V₂) volumetric flask and dilute up to the mark with distilled water.
We can calculate the concentration of the diluted solution (C₂) using the dilution rule.

Then, if we wanted to prepare the blank, that is, the solution that contains the same matrix but not the analyte, and whose concentration in iron is 0.00 mg/L, we wouldn't pipet any of the diluted solution.
To plot the calibration curve, you need to prepare iron solutions with known concentrations and measure their absorbance. You need to pipet 0 mL of the diluted solution to have 0.00 mg of iron.
Learn more: brainly.com/question/24195565