<span>vf^2 = vi^2 + 2*a*d
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vf = velocity final
vi = velocity initial
a = acceleration
d = distance
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since the airplane is decelerating to zero, vf = 0
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0 = 55*55 + 2*(-2.5)*d
d = (-55*55)/(2*(-2.5))
d = 605 meters
</span>
Answer:
Explanation:
Comment
You have to read this carefully enough that you don't mix up energy and forces.
Gravity is a force. If you don't believe me try jumping off a building. Which way are you going to go and why? Down because gravity attracts your mass.
So Magnetism must be a force as well. It acts in one direction, but not a specific one the way gravity acts). It also either attracts or repulses (pushes an object away)
Answer A
a substance dissolves.
like adding a soluble salt to water, it just dissolves, i.e dissociates homogeneously as water is able to dissociate salts (ionic compounds) into its ions. (it can also dissociate other non-ionic compounds like HCL)
the salt still remains chemically as a salt and is unchanged chemically thus it is not an indication of a chemical reaction as no chemical reaction has taken place.
the formation of a precipitate is a chemical reaction because a new substance (i.e new chemical) is formed. For example adding aqueous sodium hydroxide into an aqueous solution with CU2+ cations will form a blue precipitate (that is copper (II) hydroxide which is insoluble, hence it precipitates). Since a new chemical is formed, a chemical reaction has taken place and thus indicates a chemical reaction.
color change... im not sure but usually a color change will only occur when a new substance is formed. Like iron corrodes (i.e rust) slowly in moist air to form hydrated iron (III) oxide that is rust. (brown color).
usually adding a mixture to a mixture has little energy change, i.e little heat taken in by the reaction mixture or little heat given out by the reaction mixture. Whereas when a new substance is formed, there is usually noticeable energy change like the container gets colder or hotter (without heat being supplied of course). For example dissolving basic oxides into water releases energy ( more energy released than gained = exothermic reaction).
i think that should be the answer... hope it helped :D
C and d are the right answers
Feeling of Weight.
When walking, you feel the weight on your feet, therefore, your brain automatically refers to it as a source of weight.
In the air there is no platform to land on, therefore the brain does not have the conscience to register you getting pulled down.
