C.
Explanation: Because mirrors are lighter, and they are easier than lenses to make perfectly smooth.
<span>The big bang theory is one of the most accepted theories on the origin of the universe because of scientific evidence, such as d: distant, exploding quasars were found </span>
Answer:
Explanation:
The calcite Crystal can be identified by carrying out an acid test on it. This is done by bringing it in contact with a weak acid which cause crack in it structure. Hence a little of carbondioxide gas is released.
Since diamond is the hardest object,it can be identified on a Mohs scale. Likewise it can be tested by bringing it in contact with a newspaper, if the letters on the paper are not seen, that shows it is a pure diamond.
Window glass is identified by the code on it.
While Quartz Crystal is identified by scratch test. When it is used to scratch all other softer stones and metal, it leaves mark on them.
Answer:
~The slope of the line on a velocity vs. time graph represents acceleration.
Explanation:
~~Acceleration is equal to the ratio between the change in velocity of an object and the time taken:
a=\frac{\Delta v}{\Delta t}a=
Δt
Δv
On a velocity-time graph, this ratio corresponds to the slope of the line. In fact, \Delta vΔv corresponds to the increment in the y-value (the velocity), while \Delta tΔt corresponds to the increment in the x-value (the time), therefore their ratio corresponds to the definition of slope of the line.
Use light-years as the unit of measurement <span />