Answer:
The frequency heard by the motorist is 4313.2 Hz.
Explanation:
let f1 be the frequency emited by the police car and f2 be the frequency heard by the motorist, let v1 be the speed of the police car and v2 be the speed of the motorist and v = 343 m/s be the speed of sound.
because the police car is moving towards the motorist at a higher speed, then the motorist will hear a increasing frequency and according to Dopper effect, that frequency is given by:
f1 = [(v + v2/(v - v1))]×(f2)
= [( 343 + 30)/(343 - 36)]×(3550)
= 4313.2 Hz
Therefore, the frequency heard by the motorist is 4313.2 Hz.
Answer:
Explanation:
For parallel inductors ,
For series combination
Total inductance
= 16.67 + 20
= 36.67 mH .
reactance of total inductance at 300 kHz
= ω
where ω is angular frequency
= 2πf
= 2 x 3.14 x 300 x 10³ x 36.67 x 10⁻³
= 69.1 x 10³ ohm
Total rms current = Vrms / reactance
= 60 / 69.1 x 10³ A
= .87 x 10⁻³ A
= .87 mA
That's false. Mechanical waves (like sound and ocean waves) do
need a medium to travel in, but electromagnetic waves (like radio
and light) don't.
Electromagnets are used in home appliances quite regularly and are used even in simple home appliances. Common home appliances that use electromagnets are toasters, printers, and microwave ovens. Electromagnets are a certain type of magnet that does not function unless an electrical current flows through it. These appliances create the magnetic field by flowing electricity through certain parts of the appliance.
