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.
For the first question, you got them right, for the two you left blank, initial(beginning) velocity: 2 m/s the final velocity is: 12 m/s
Yes, it is diffusion !
Diffusion is the process in which gas, through random movement of particles, tends to fill up the whole volume of the container in which it is placed. So a similar process would lead the smoke, which is in form of gas (or light particles), to fill in the whole room in which it is contained.
Every organism may classified into seven level of classifications, such that each level contains organisms with similar characteristics. Kingdom is the largest and the broadest level of classification while species is the smallest and most specific level of classification. Therefore from the largest to the smallest the order is as follows:
Kingdom
Phylum
Class
Order
Family
Genus
Species
Answer:=14,160 kJ
Explanation: Let m1 and m2 be the initial and final amounts of mass within the tank, respectively. The steam properties are listed in the table below
Specific Internal SpecificTemp Pressure Volume Energy Enthalpy Quality Phase
C MPa m^3/kg kJ/kg kJ/kg
1 260 4.689 0.02993 2158 2298 0.7 Liquid Vapor Mixture
2 260 4.689 0.0422 2599 2797 1 Saturated Vapor
The mass initially contained in the tank is m1 = V/v1
m1 =0.85 m^3 /0.02993 m^3 /kg
= 28.4 kg
The mass finally contained in the tank is
m2 =V2/v
= 0.85 m^3 /0.0422 m^3 /kg
= 20.14 kg
The heat transfer is then
Qcv = m2u2 − m1u1 − he(m2 − m1)
Qcv = (20.14)(2599) − (28.4)(2158) − (2797)(20.14 − 28.4) = 14,160 kJ
