Answer:
A) 60%
B) p2 = 1237.2 kPa
v2 = 0.348 m^3
C) w1-2 = w3-4 = 1615.5 kJ
Q2-3 = 60 kJ
Explanation:
A) calculate thermal efficiency
Л = 1 - 
where Tl = 300 k
Th = 750 k
hence thermal efficiency ( Л ) = [1 - ( 300 / 750 )] * 100 = 60%
B) calculate the pressure and volume at the beginning of the isothermal expansion
calculate pressure ( P2 ) :
= P3v3 = mRT3 ----- (1)
v3 = 0.4m , mR = 2* 0.287, T3 = 750
hence P3 = 1076.25
next equation to determine P2
Qex = p3v3 ln( p2/p3 )
60 = 1076.25 * 0.4 ln(p2/p3)
hence ; P2 = 1237.2 kpa
calculate volume ( V2 )
p2v2 = p3v3
v2 = p3v3 / p2
= (1076.25 * 0.4 ) / 1237.2
= 0.348 m^3
C) calculate the work and heat transfer for each four processes
work :
W1-2 = mCv( T2 - T1 )
= 2*0.718 ( 750 - 300 ) = 1615.5 kJ
W3-4 = 1615.5 kJ
heat transfer
Q2-3 = W2-3 = 60KJ
Q3-4 = 0
D ) sketch of the cycle on p-V coordinates
attached below
Answer:
(a) θ = 33.86°
(b) Ay = 49.92 N
Explanation:
You have that the magnitude of a vector is A = 89.6 N
The x component of such a vector is Ax = 74.4 N
(a) To find the angle between the vector and the x axis you use the following formula for the calculation of the x component of a vector:
(1)
Ax: x component of vector A
A: magnitude of vector A
θ: angle between vector A and the x axis
You solve the equation (1) for θ, by using the inverse of cosine function:
the angle between the A vector and the x axis is 33.86°
(b) The y component of the vector is given by:
the y comonent of the vecor is Ay = 49.92 N
Answer:
A - elastic since many other fast food items could be considered close substitutes.
Explanation:
The price elasticity of demand is how much the demand of the Big Macs will change due to a 1% change in price. Should the elasticity be greater than 1, the Big Macs will be elastic. Should it be less than 1, the Big Macs are inelastic.
Demand elasticity is calculated as the percentage change in quantity demanded divided by a percentage change in price.
Since Big Macs are (i) a luxury good, and (ii) have close substitutes (other burgers available at McDonalds and other fast food stores), we will say their elasticity is greater than 1.
This means that the demand of Big Macs will change due to a 1% increase in price due to the presence of close substitutes.
Answer:
that is going at a constant rate
Explanation:
