It’s the crest, the crest is the top part of the wave and the trough is the bottom so they correspond
Answer:
using cleats other than gym shoes
Explanation:
the cleats hwve spikes and help gain speed
Answer:
If the frequency of the source is increased the current in the circuit will decrease.
Explanation:
The current through the circuit is given as;
Where;
V is the voltage in the AC circuit
Z is the impedance
Where;
R is the resistance
is the inductive reactance
= ωL = 2πfL
where;
L is the inductance
f is the frequency of the source
Finally, the current in the circuit is given as;
From the equation above, an increase in frequency (f) will cause a decrease in current (I).
Therefore, If the frequency of the source is increased the current in the circuit will decrease.
Answer:
Energy
A wave is a disturbance that carries energy from one place to another through matter and space.
Explanation:
A wave can be defined as a form of disturbance that carries energy from one place to another through matter and space.
The energy of wave depends on the frequency of the wave and the wavelength (lambda) of that particular wave.
Mathematically,
V = f × lambda
Answer:
The BOD concentration 50 km downstream when the velocity of the river is 15 km/day is 63.5 mg/L
Explanation:
Let the initial concentration of the BOD = C₀
Concentration of BOD at any time or point = C
dC/dt = - KC
∫ dC/C = -k ∫ dt
Integrating the left hand side from C₀ to C and the right hand side from 0 to t
In (C/C₀) = -kt + b (b = constant of integration)
At t = 0, C = C₀
In 1 = 0 + b
b = 0
In (C/C₀) = - kt
(C/C₀) = e⁻ᵏᵗ
C = C₀ e⁻ᵏᵗ
C₀ = 75 mg/L
k = 0.05 /day
C = 75 e⁻⁰•⁰⁵ᵗ
So, we need the BOD concentration 50 km downstream when the velocity of the river is 15 km/day
We calculate how many days it takes the river to reach 50 km downstream
Velocity = (displacement/time)
15 = 50/t
t = 50/15 = 3.3333 days
So, we need the C that corresponds to t = 3.3333 days
C = 75 e⁻⁰•⁰⁵ᵗ
0.05 t = 0.05 × 3.333 = 0.167
C = 75 e⁻⁰•¹⁶⁷
C = 63.5 mg/L
