Answer:
D. Radar uses radio, and the siren uses sound waves.
Explanation:
The main difference between the siren passing by and the radar is that radar uses radio waves and siren uses sound waves.
- Sound waves are mechanical waves which requires a material medium for their propagation.
- In a vacuum, the sound waves cannot pass through freely.
- Radar is an electromagnetic wave.
- It is particular of radio waves origin.
- Such waves do not require a material medium for their propagation and hence can be transmitted through a vacuum.
<span>Suppose you plant a seed and observe that a tree of large mass grows from it. The tree achieves a final mass that changes very little for years afterward.<span>
</span>Answer: Of the options presented above the one that is true about the tree is answer choice B) Both anabolic and catabolic reactions took place in the seed and tree when it was young and growing, and both continue now even though the tree reached a stable mass.
I hope it helps, Regards.</span>
Evaporating? But that’s with a boiling liquid
Aluminium reacts with dilute sulfuric acid based on the following reaction:
<span>2Al + 3H2SO4 ..............> Al2 (SO4)3 + 3H2
From the periodic table:
mass of aluminium = 27 grams
mass of hydrogen = 1 gram
mass of oxygen = 16 grams
mass of sulfur = 32 grams
Therefore:
molar mass of aluminium = 27 grams
molar mass of sulfuric acid = 2(1) + 32 + 4(16) = 98 grams
From the balanced chemical equation:
2 moles of aluminium react with 3 moles of dilute sulfuric acid.
This means that 34 grams of Al react with 294 grams of the acid
To get the amount of aluminium that reacts with </span><span>5.890 g of sulfuric acid, we will do cross multiplication as follows:
</span>amount of Al = (<span>5.890 x 34) / 294 = 0.6811 grams</span>
Battery represents a simple machine
