Assessing Balloon Error
Goal for mass to be lifted=332 g
Actual mass lifted = 200 g
1. What was the biggest part of your downward force? Did this surprise you?
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(data is missing here)
2. With our hot air balloons, what were we changing about our balloon to get it to float?
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(data is missing here)
3. What is buoyancy?
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According to Wikipedia, “bouyancy is a force exerted by a liquid, gas or other fluid, that opposes an object's weight.” In the case of a hot air balloon, the opposing force would be the atmosphere itself.
4. What two states of matter are included as a possible fluid?
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Gas and liquid.
5. (Question is missing here)
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You have to know the density- and the objects density has to be less than the thing you want it to float in- air/water.
6. Can a hot air balloon lift more on a hot day or a cold day? Why?
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A hot air balloon can lift more on a cold day because colder air is denser than hot air, and it is the difference in density between the atmosphere and the air in the balloon that produces lift. The colder the air, the greater the difference.
7. Imagine a sealed balloon that has a volume of 11,500 cm3. (It had a radius of 14cm just to give you an idea of the size of the balloon.) It is NOT floating. How much air did it displace?
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It will displace its own volume, so it will displace 11,500 cm3.
8. What must be true about the air it displaced as compared to the downward force?
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The air it displaced will have an opposing force less than or equal to that of the balloon.
9. Imagine a second sealed balloon with the same volume. It is filled with helium and floats upward. If the density of the air is .00125 g/cm3, what is the buoyant force?
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B = pgV
= .00125 g/cm3 (9.81 m/s2)(11,500 cm3)
= 141.01875mg/s2
10. Ron White, a comedian, said “It’s not THAT the wind’s a blowin’, it’s WHAT the wind’s a blowin’.” Explain how this relates to this unit in terms of force and air pressure and air mass.
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If the wind is blowing colder air, the balloon will rise faster and higher. If the wind is blowing warmer air, the balloon will rise slower and less high. If the air’s composition makes it less dense, then the balloon will rise slower and lower; but if the air is denser for some reason, then the balloon will rise faster and higher.