Answer: The frequency heard will be f = 275.675Hz
Explanation: When an object emitting sound is moving, it occurs a phenomenon called Doppler shift or Doppler effect. What happens is that the sound gets higher when the moving object comes closer the observer and becomes lower after it passes, This change is due to the quantity of waves that passes through an area in an unit of time.
The formula to calculate the Doppler effect is as follows
f = (
) · f₀
f is the observed frequency;
c is the speed of sound;
Vs is velocity of the source;
f₀ is the emitted frequency of source;
Substituting and calculating,
f = 
· 300
f = 275.675 Hz
Thus, the frequency heard by the police officer is 275.675Hz.
Hi there!
We can use Newton's Second Law:
∑F = net force (N)
m = mass (kg)
a = acceleration (m/s²)
We are given the mass and acceleration, so:
∑F = 20 · 2 = <u>40 N</u>
Answer:
As the capacitor is discharging, the current is increasing
Explanation:
Lets take
C= Capacitance
L=Inductance
V=Voltage
I= Current
The total energy E given as
We know that total energy E is conserved so when electric energy 1/2 CV² decreases then magnetic energy 1/2 IL² will increases.
It means that when charge on the capacitor decreases then the current will increase.
As the capacitor is discharging, the current is increasing
Answer:
1.24 m/s
Explanation:
Metric unit conversion:
9.25 mm = 0.00925 m
5 mm = 0.005 m
The volume rate that flow through the single pipe is
This volume rate should be constant and divided into the 4 narrower pipes, each of them would have a volume rate of
So the flow speed of each of the narrower pipe is:
Answer:This is an explanation
for 150 km its all ik i tried hard ty
Explanation:The car covers 150 km in 3 hours or 3*60 = 180 minutes.
So in 12 min the car will cover (12/180)*150 = 10 km.
