Answer:
t = 4.0 min
Explanation:
given data:
diameter of rod = 2 cm
T_1 = 100 degree celcius
Air stream temperature = 20 degree celcius
heat transfer coefficient = 200 W/m2. K
WE KNOW THAT
copper thermal conductivity = k = 401 W/m °C
copper specific heat Cp = 385 J/kg.°C
density of copper = 8933 kg/m3
charateristic length is given as Lc
Biot number is given as 
Bi = 0.0025
As Bi is greater than 0.1 therefore lumped system analysis is applicable
so we have
............1
where b is given as
b = 0.01163 s^{-1}
putting value in equation 1
solving for t we get
t = 4.0 min
Answer:
A. 91 meters north
Explanation:
Take +y to be north.
Given:
v₀ = 13 m/s
a = 0 m/s²
t = 7 s
Find: Δy
Δy = v₀ t + ½ at²
Δy = (13 m/s) (7 s) + ½ (0 m/s²) (7 s)²
Δy = 91 m
The displacement is 91 m north.
The force of friction is given by:
f = μR, where μ is the friction coefficient and R is the reaction force, which will be equal to the weight.
100 = μ x 130
μ = 0.77
The correct answer is the one with 45000 kg*km/hr.
the formula is p = m*v
900 *50/hr giving u 45000
I know this is the correct answer because i have already turned it in and got a 100%.
Answer:
Re = 1 10⁴
Explanation:
Reynolds number is
Re = ρ v D /μ
The units of each term are
ρ = [kg / m³]
v = [m / s]
D = [m]
μ = [Pa s]
The pressure
Pa = [N / m²] = [Kg m / s²] 1 / [m²] = [kg / m s²]
μ = [Pa s] = [kg / m s²] [s] = [kg / m s]
We substitute the units in the equation
Re = [kg / m³] [m / s] [m] / [kg / m s]
Re = [kg / m s] / [m s / kg]
RE = [ ]
Reynolds number is a scalar
Let's evaluate for the given point
Where the data for methane are:
viscosity μ = 11.2 10⁻⁶ Pa s
the density ρ = 0.656 kg / m³
D = 2 in (2.54 10⁻² m / 1 in) = 5.08 10⁻² m
Re = 0.656 4 2 5.08 10⁻² /11.2 10⁻⁶
Re = 1.19 10⁴
