The best answer would be:
B. Epi pen
Here is more about it:
An epi pen injects epinephrine into the body to counteract the effects of an allergic reaction. Epinephrine helps narrow blood vessels and open up the airways. This can be used for food allergies, insect bites, and some other allergens. It is very effective and immediately works, but it is short-lived, so seeking medical attention after is still needed.
1) See attached figure
The relationship between charge and current is:
where
i is the current
Q is the charge
t is the time
Therefore, the current is the rate of change of the charge passing through a given point over time.
This means that for a graph of charge over time, the current is just equal to the slope of the graph.
For the graph in this problem:
- Between t = 0 and t = 2 s, the slope is
therefore the current is
i = 25 A
- Between t = 2 s and t = 6 s, the slope is
therefore the current is
i = -25 A
- Between t = 6 s and t = 8 s, the slope is
therefore the current is
i = 25 A
The figure attached show these values plotted on a graph.
2)
The previous equation can be rewritten as
This equation is valid if the current is constant: if the current is not constant, then the total charge is simply equal to the area under a current vs time graph.
Here we have the current vs time graph, so we gave to find the area under it.
The area of the first triangle is:
While the area of the second square is
So, the total area (and the total charge) is
Answer:
a) 431 Hz
b) 429 Hz
c) 403 Hz
Explanation:
The frequency you heard is calculated using the relation
f = f(s) / [1 - (v(s)/v) ]
f = 400 / [1 - 25/343]
f = 400 / (1 - 0.0729)
f = 400 / 0.9271
f = 431.5 Hz
The frequency your friend starts hearing is
f = f(s) * [1 + (v(s)/v) ]
f = 400 * [1 + 25/343]
f = 400 * (1 + 0.0729)
f = 400 * 1.0729
f = 429.2 Hz
when you're next to each other and you are hearing 3 beats per second. The frequency you're singing is 400 + 3 Hz
403 Hz