Answer:
They create enormous amounts of sound energy, much like explosion. When an aircraft passes through air, it creates a series of pressure waves just like the waves created by the boat. As the speed of aircraft increases these waves are forced to compress.
Answer:
the Earth's crust is broken into about 12 plates that float on hotter, softer rocks in the underlying mantle
Explanation:
Answer:
5 units to the left
Explanation:
I had the same question :)
1) See attached graph
To solve this part of the problem, we have to keep in mind the relationship between current and charge:
where
i is the current
Q is the charge
t is the time
The equation then means that the current is the rate of change of charge over time.
Therefore, if we plot a graph of the charge vs time (as it is done here), the current at any time will be equal to the slope of the charge vs time graph.
Here we have:
- Between t = 0 and t = 2 s, the slope is , so the current is 25 A
- Between t = 2 s and t = 6 s, the slope is , so the current is -25 A
- Between t = 6 s and t = 8 s, the slope is , so the current is 25 A
Plotting on a graph, we find the graph in attachment.
2)
The relationship we have written before
Can be rewritten as
This is valid for a constant current: if the current is not constant, then the total charge is simply equal to the area under the current vs time graph.
Therefore, we need to find the area under the graph.
Here we have a trapezium, where the two bases are
A = 1 ms = 0.001 s
B = 2 ms = 0.002 s
And the height is
h = 10 mA = 0.010 A
So, the area is
So, the charge is .
We can base this on the equation of thermal expansion.
ΔL = L₀αΔT
where
ΔL is the expansion of length upon heating
L₀ is the initial length
α is the coefficient of linear expansion
ΔT is the temperature difference
So, if α for Aluminum is greater than α for Copper, then after heating, aluminum would be longer than copper.