Answer:
C
Explanation:
Vector A points up
Vector B points right
The combination must be both up and right which is C
Answer:
a) technician A
Explanation: A parking brake is a secondary and support brake system which is usually applied when the vehicle is not in motion,this is done to prevent any form of motion and the possibility of any form of accident.
A secondary circuit is a circuit or coil in which current is generated through induction from another circuit or coil called the primary circuit,it has not been discovered that a low pressure from that circuit has led to poor trailer parking brake performance.
A) 
The magnitude of the capacitive reactance is given by
where
is the angular frequency
C is the capacitance
While the magnitude of the inductive capacitance is given by
where L is the inductance.
Since we want the two reactances to be equal, we have
So we find
B) 7449 rad/s
In this case, we have
is the inductance
is the capacitance
Therefore, substituting in the formula for the angular frequency, we find
C) 
Now we can us the formulas of the reactances written in part A). We have:
- Capacitive reactance:
- Inductive reactance:
Frequency heard by listener: fl = ?
frequency of source: fs = 300 Hz
velocity of listener: vl = 16 m/s
velocity of source: vs = 0
<span>velocity of sound in air: c = 344 m/s
</span><span>fl = fs [(c – vl)/c] = 300[(344-16)/344]
</span> =286.04 Hz
