Answer:
497.00977 N
3742514.97005
Explanation:
= Density of water = 1000 kg/m³
C = Drag coefficient = 0.09
v = Velocity of dolphin = 7.5 m/s
r = Radius of bottlenose dolphin = 0.5/2 = 0.25 m
A = Area
Drag force
![F_d=\frac{1}{2}\rho CAv^2\\\Rightarrow F_d=\frac{1}{2}\times 1000 \times 0.09(\pi 0.25^2)7.5^2\\\Rightarrow F_d=497.00977\ N](https://tex.z-dn.net/?f=F_d%3D%5Cfrac%7B1%7D%7B2%7D%5Crho%20CAv%5E2%5C%5C%5CRightarrow%20F_d%3D%5Cfrac%7B1%7D%7B2%7D%5Ctimes%201000%20%5Ctimes%200.09%28%5Cpi%200.25%5E2%297.5%5E2%5C%5C%5CRightarrow%20F_d%3D497.00977%5C%20N)
The drag force on the dolphin's nose is 497.00977 N
at 20°C
= Dynamic viscosity = ![1.002\times 10^{-3}\ Pas](https://tex.z-dn.net/?f=1.002%5Ctimes%2010%5E%7B-3%7D%5C%20Pas)
Reynold's Number
![Re=\frac{\rho vd}{\mu}\\\Rightarrow Re=\frac{1000\times 7.5\times 0.5}{1.002\times 10^{-3}}\\\Rightarrow Re=3742514.97005](https://tex.z-dn.net/?f=Re%3D%5Cfrac%7B%5Crho%20vd%7D%7B%5Cmu%7D%5C%5C%5CRightarrow%20Re%3D%5Cfrac%7B1000%5Ctimes%207.5%5Ctimes%200.5%7D%7B1.002%5Ctimes%2010%5E%7B-3%7D%7D%5C%5C%5CRightarrow%20Re%3D3742514.97005)
The Reynolds number is 3742514.97005
(a) 0.249 (24.9 %)
The maximum efficiency of a heat engine is given by
![\eta = 1-\frac{T_C}{T_H}](https://tex.z-dn.net/?f=%5Ceta%20%3D%201-%5Cfrac%7BT_C%7D%7BT_H%7D)
where
Tc is the low-temperature reservoir
Th is the high-temperature reservoir
For the engine in this problem,
![T_C = 270^{\circ}C+273=543 K](https://tex.z-dn.net/?f=T_C%20%3D%20270%5E%7B%5Ccirc%7DC%2B273%3D543%20K)
![T_H = 450^{\circ}C+273=723 K](https://tex.z-dn.net/?f=T_H%20%3D%20450%5E%7B%5Ccirc%7DC%2B273%3D723%20K)
Therefore the maximum efficiency is
![\eta = 1-\frac{T_C}{T_H}=1-\frac{543}{723}=0.249](https://tex.z-dn.net/?f=%5Ceta%20%3D%201-%5Cfrac%7BT_C%7D%7BT_H%7D%3D1-%5Cfrac%7B543%7D%7B723%7D%3D0.249)
(b-c) 0.221 (22.1 %)
The second steam engine operates using the exhaust of the first. So we have:
is the high-temperature reservoir
is the low-temperature reservoir
If we apply again the formula of the efficiency
![\eta = 1-\frac{T_C}{T_H}](https://tex.z-dn.net/?f=%5Ceta%20%3D%201-%5Cfrac%7BT_C%7D%7BT_H%7D)
The maximum efficiency of the second engine is
![\eta = 1-\frac{T_C}{T_H}=1-\frac{423}{543}=0.221](https://tex.z-dn.net/?f=%5Ceta%20%3D%201-%5Cfrac%7BT_C%7D%7BT_H%7D%3D1-%5Cfrac%7B423%7D%7B543%7D%3D0.221)
Answer:
pretty sure its B if it isnt im so so sorry
Explanation:
Answer:
what are u asking there isnt a question
Answer:
As much I know the gravity on moon is 1.62m/s२.