Answer:
I world say A is the answer 80% sure
Answer:
t=4.86s
Explanation:
To find the wavelength you use the following formula:
v: speed of sound = 343m/s
f: frequency = 400Hz
λ: wavelength of the sound
By doing λ the subject of the formula and replacing the values of f and v you obtain:
Now, to calculate the time that sound takes to reach the last row you use:
t: time
d: distance to the last row = 1947m
hence, the time is 4.86s
Answer:
b: false
Explanation:
It's true that endothermic reactions absorb heat from their surrounding. But this makes the surroundings cooler, not warmer.
Answer:
The reactance of the capacitor
Explanation:
In an AC circuit containing different elements (capacitors, resistors and inductors), we cannot simply calculate the equivalent resistance of the circuit, so another quantity is used, which is called reactance.
For a capacitor, the reactance is given by:
where:
f is the frequency of the AC current in the circuit
C is the capacitance of the capacitor
The reactance has a similar meaning to that of the resistance for a DC current. In fact, we notice that:
- When f=0 (which means we are in regime of DC current, because the current never changes direction), the reactance is infinite. This is correct: in a DC circuit, the capacitor does not let current pass through it, so it like it has infinite resistance (=infinite reactance)
- When f tends to infinite, the reactance becomes zero: in such situation, the current in the circuit changes direction so quickly that the capacitor has no enough time to "block" the current in the circuit, so it like it has almost zero resistance (zero reactance).
Answer:
Wavelength = 10 m
Explanation:
Given:
Speed = 100 m
Frequency = 10 Hz = 10
To find : Wavelength = ?
We know that the relationship between wavelength λ, frequency f and speed v is given by the equation
v = fλ
Therefore wavelength λ = v/f
= 100 m / 10 m
= 10 m
Hence wavelength = 10 m