In your own words, describe why melting ice with salt freezes cream. Compare your descriptions to your classmates and describe how you could change the setup to freeze the cream faster, to produce colder temperatures or to cool other substances.
Answers
By adding salt to the ice-creams, it lowers its melting point and allows the ice cream to freeze cohesively. When salt is added to ice, the equilibrium is reached and kept at lower temperature.
How salt lowers the freezing point of ice?
When water reaches 32°F ( 0°C ), It turns into ice. At this temperature, The water molecules and ice molecules are interacting. If the temperature increases, more water become ice.
When the ionic compound salt is added, it lowers the freezing point of water. This concept is called "Freezing point depression". Freezing point depression is a drop in the minimum temperature at which substance freezes, caused when a smaller amount of another, non-volatile substance.
When salt added to the ice, the freezing point reduces from zero to negative value of degree Celsius -9°C( 15°F ), The temperature of salt is too cold for the salt to dissolve into the ice.
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Answer:
Water normally freezes at 0°C (32°F). Salt lowers the freezing temperature. (That is, it can remain a liquid at much lower temperatures.)
When sprinkled on ice, the salt lowers the freezing temperature of the water which effectively melts the ice when the salt dissolves into it. There is a limit to how low it can reduce the temperature, though. If the temperature drops below -9°C (15°F), it's too cold for the salt to dissolve into the ice.
When making ice cream, the salt lowers the temperature of the ice and water sufficiently enough to freeze the cream.
Related Questions
Which wavelength region is most useful for investigating dense cores inside giant molecular clouds?
The largest mass extinction event in the history of the Earth occurred at the end of the _______ period.
Which of the following would have the highest power rating? 500 J of energy used in 100 seconds 1,000 J of energy used in 100 seconds 500 J of energy used in 50 seconds 1,000 J of energy used in 50 seconds
Determine the conversion factor between (a) km/h and mi/h, (b) m/s and ft/s, and (c) km/h and m/s.
Answers
Answer:
1,803,036.67 W
Explanation:
Data provided in the question:
People per hour that can be moved by lift = 49800
Height of movement, h = 190 m
Average mass per person = 70 kg
Now,
Power = Rate of doing work
Thus,
Power = ΔU
= mgh
here,
m = total mass
g = acceleration due to gravity
or
Power = (70kg × 49800)(9.8)(190)
or
Power = 6,490,932,000 J per hour
also,
Watt = Joule/second
Therefore,
Power = 6,490,932,000 ÷ 3600
= 1803036.67 W
Final answer:
To estimate the maximum total power needed for Squaw Valley ski area to move 49800 people per hour on their lifts, we calculate the work done per person per hour and then divide it by the time taken to travel vertically by 190 m. The estimated maximum total power needed is 3.31 x 10^8 W.
Explanation:
To estimate the maximum total power needed to move 49800 people per hour on a skilift at Squaw Valley, we can calculate the work done per person per hour and then divide it by the time taken to travel vertically by 190m. The work done is equal to the potential energy gained, which is given by the formula mgh, where m is the average mass per person (70 kg), g is the acceleration due to gravity (9.8 m/s^2), and h is the vertical height gained (190 m). Multiplying this by the number of people per hour gives us the total work done per hour. Dividing this by the time taken to travel the vertical height gives us the maximum power needed. The power is given by the formula P = W/t, where W is the work done and t is the time taken.
Using the given values, we have:
Work done per person per hour: (70 kg) x (9.8 m/s^2) x (190 m) = 128660 J
Total work done per hour: 128660 J x 49800 = 6.40 x 10^9 J
Time taken to travel vertically by 190m: 190 m / (9.8 m/s^2) = 19.39 s
Maximum power needed: (6.40 x 10^9 J) / (19.39 s) = 3.31 x 10^8 W
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Answers
Answer:
It also increases
Explanation:
The strength of the gravitational force between two objects depends on two factors, mass, and distance. the force of gravity the masses exert on each other. If one of the masses is doubled, the force of gravity between the objects is doubled. increases, the force of gravity decreases.
Part A
In this experiment, you will place the container in the freezer. What do you think will happen?
Answers
Hypothesis: When the container with the balloon and plaster of Paris is placed in the freezer, the water inside the balloon will freeze and expand as it turns into ice. As the water freezes, it will exert pressure on the plaster, causing the plaster to crack or deform. The extent of cracking or deformation may depend on the strength and thickness of the plaster.
Part B of the experiment would typically involve conducting the experiment and observing the actual outcome to confirm or reject the hypothesis.
Answers
the diagonal of the car, at 5m/s, that speed is relative to the floor of the car.
The reason I have to assume that is because I think it makes the problem
easier. I could be wrong. And it's still troubling, because 5 m/s is a hefty
11.18 mph, which is a pretty energetic walk. (In fact, it's a 5min 22sec mile,
which I for one never accomplished, even when I was running.) But so be it.
-- The length of the car's diagonal is √(3² + 15²) = √(9 + 225) = √334
-- The angle of his walk along the diagonal is the angle whose tangent is 3/15.
-- His velocity consists of the components [ 5 cos(angle) east ] and
[ 5 sin(angle) north ].
That's [ 5 x 15/√334 east ] and [ 5 x 3/√334 ] north .
The train's motion adds to the easterly component of his velocity,
and that becomes [ (2.5) + (5 x 15/√334) ] . The train's motion has
no effect on the northerly component of his velocity.
So now we're ready to put the components together and find his velocity
relative to the tracks. I think it'll be easier to go ahead and get the numerical
value of each component, and then combine them.
Easterly component: (2.5) + (5 x 15/√334) = 6.6038 m/s
Northerly component: 5 x 3/√334 = 0.8208 m/s
Just before finding the magnitude, we note that the direction of his velocity
is (the angle whose tangent is 0.8208/6.6038) north of east. That's about
7.085 degrees north of east ...the compass bearing of 82.92 degrees.
Now for the magnitude. It's the square root of the sum of the squares of
the easterly component and the northerly component.
√ (6.6038² + 0.8208²) = √44.2841 = 6.655 m/s
(All numbers are rounded.)
That's my story, and I'm sticking with it.
Answers
I used the Lens Equation:
Where:
obj. is the distance of the object
im. is the distance of the image
f is the focal length
Final answer:
The image formed by the convex lens is real, located 10.91 cm to the right of the lens, and is inverted. The ray diagram would show rays from the object converging at the image point after passing through the lens.
Explanation:
In order to draw a ray diagram and find the location of the image for an object placed 30.0 cm to the left of a convex lens with a focal length of +8.0 cm, we first utilize what is known as the lens formula, which is 1/f = 1/do + 1/di. Here, f is the focal length of the lens, do is the object distance, and di is the image distance.
In the given question, the object distance (do) is -30 cm (the negative sign indicates that the object is on the same side of the lens as the light source), and the focal length (f) is +8 cm. Plugging these values into the lens equation, we find that 1/di = 1/f - 1/do = 1/8 - 1/(-30). Solving this, we get di = 10.91 cm.
This positive value for di means the image is real, meaning it can be projected onto a screen, and appears on the opposite side of the lens from where the object is. The magnitude of the image distance indicates the image is 10.91 cm from the lens.
To determine the orientation of the image, we use the magnification formula, m = -di/do. Substituting the given values into this formula, we get m = -10.91 / -30 = +0.36. Since this value is positive, the image is inverted. The image would appear smaller than the object because the absolute value of the magnification is less than 1.
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condensation
convection
collaboration
Answers
Answer is C. Convection