Answer:
a) The velocity of the car is 7.02 m/s and the car is approaching to the police car as the frequency of the police car is increasing.
b) The frequency is 1404.08 Hz
Explanation:
If the police car is a stationary source, the frequency is:
(eq. 1)
fs = frequency of police car = 1200 Hz
fa = frequency of moving car as listener
v = speed of sound of air
vc = speed of moving car
If the police car is a stationary observer, the frequency is:
(eq. 2)
Now,
fL = frequecy police car receives
fs = frequency police car as observer
a) The velocity of car is from eq. 2:

b) Substitute eq. 1 in eq. 2:

A wave that is oscillation of matter.. such as a water ripples
Se necesita 105 j de trabajo para mover 2,7 c de carga de la placa negativa a la placa positiva de un condensador de placa paralela. Qué diferencia de tensión existe entre las placas
Answer:
0.88752 kgm²
0.02236 Nm
Explanation:
m = Mass of ball = 1.2 kg
L = Length of rod = 0.86 m
= Angle = 90°
Rotational inertia is given by

The rotational inertia is 0.88752 kgm²
Torque is given by

The torque is 0.02236 Nm
Answer:
a) according to Faraday's law
, b) creating a faster movement, placing more turns on coil
Explanation:
a) The voltage is induced in the coil by the relative movement between it and the magnet, therefore according to Faraday's law
E = - d (B A) / dt
In this case, the magnet is involved, so the value of the magnetic field varies with time, since the number of lines that pass through the loop changes with movement.
This voltage creates a current that charges the battery
b) There are several ways to increase the voltage
* creating a faster movement, can be done by the user
* placing more turns on the coil, must be done by the manufacturer