Answer:
Index of expansion: 4.93
Δu = -340.8 kJ/kg
q = 232.2 kJ/kg
Explanation:
The index of expansion is the relationship of pressures:
pi/pf
The ideal gas equation:
p1*v1/T1 = p2*v2/T2
p2 = p1*v1*T2/(T2*v2)
500 C = 773 K
20 C = 293 K
p2 = 35*0.1*773/(293*1.3) = 7.1 bar
The index of expansion then is 35/7.1 = 4.93
The variation of specific internal energy is:
Δu = Cv * Δt
Δu = 0.71 * (20 - 500) = -340.8 kJ/kg
The first law of thermodynamics
q = l + Δu
The work will be the expansion work
l = p2*v2 - p1*v1
35 bar = 3500000 Pa
7.1 bar = 710000 Pa
q = p2*v2 - p1*v1 + Δu
q = 710000*1.3 - 3500000*0.1 - 340800 = 232200 J/kg = 232.2 kJ/kg
Answer:12.28m/s
Explanation:
momentum of baseball =mass of baseball x velocity of baseball
Momentum of baseball =0.31x21
Momentum of baseball =6.51kgm/s
For a softball to have same momentum with the baseball we can say :momentum of baseball =mass of softball x velocity of softball
6.51=0.53 x velocity of softball
Velocity of softball =6.51/0.53
Velocity of softball =12.28m/s
It is true that there are two types of addiction, psychological and
physical. When it comes to physical addiction, it normally refers to
drug withdrawal or drug usage, when your body is exhibiting various
symptoms of needing drugs. Mental addiction refers to when there is no
actual need to use the object of addiction, but rather a mental desire
to use it and have it again.
<span>Wind power is produced from the
wind turbines or sails that uses air flow to convert it into mechanical power. It
is an alternative to fossil fuel burning, it is all around, renewable, clean,
produces no greenhouse gases and uses little land. The advantages of wind power
have been greatly praised by many. However, it has disadvantages. Wind power
especially at farm is noisy and may spoil the view for their neighboring people.
Also the amount of electricity depends on the strength of the wind. If no wind
is around, no electricity is produced. </span>
