Answer:
The frequency of sound heard by the boy is 1181 Hz.
Explanation:
Given that,
Frequency of sound from alarm
Speed = -8.25 m/s
Negative sign show the boy riding away from the car
Speed of sound = 343
We need to calculate the heard frequency
Using formula of frequency
Where, = frequency of source
= speed of observer
= speed of source
= speed of sound
Put the value into the formula
here, source is at rest
Hence, The frequency of sound heard by the boy is 1181 Hz.
Answer:
The conductivity of Nichrome is .
Explanation:
Given:
Potential difference (V) = 2.0 V
Current flowing (I) = 4.0 A
Length of wire (L) = 1.0 m
Area of cross section of wire (A) = 1.0 mm² = 1 × 10⁻⁶ m² [1 mm² = 10⁻⁶ m²]
We know, from Ohm's law, that the ratio of voltage and current is always a constant and equal to the resistance of the resistor. Therefore, the resistance of the nichrome wire is given as:
Now, resistance of the nichrome wire in terms of its resistivity, length and area of cross section is given as:
Where,
Now, plug in all the values given and solve for . This gives,
Now, conductivity of a material is the reciprocal of its resistivity. Therefore, the conductivity of Nichrome is given as:
Conductivity is measured in Siemens per meter (S/m)
Therefore, the conductivity of Nichrome is .