Answer:
v = 40 m/s
Explanation:
Difference in the height of the two columns:

Air density, 
Water density, 
The velocity of air flow is given by the equation:

Answer:
k = 0.1118 per min
Explanation:
Assume;
Initial number of bacteria = N0
Number of bacteria IN 'T' time = Nt
So,
![Nt=N0e^{-kt}\\\\in\ 6.2 min\\\\\\frac{N0}{2}= N0e^{-k(6.2)}\\\\ln\frac{1}{2} = -k[6.2]](https://tex.z-dn.net/?f=Nt%3DN0e%5E%7B-kt%7D%5C%5C%5C%5Cin%5C%206.2%20min%5C%5C%5C%5C%5C%5Cfrac%7BN0%7D%7B2%7D%3D%20N0e%5E%7B-k%286.2%29%7D%5C%5C%5C%5Cln%5Cfrac%7B1%7D%7B2%7D%20%3D%20-k%5B6.2%5D)
k = 0.1118 per min
Answer:
Change in length = 0.1257 mm
Change in diameter= -0.03771mm
Explanation:
Given
Diameter, d = 15 mm
Length of rod, L = 200mm
F = Force= 300N
d = 0.015m
Ep=2.70 GPa, np=0.4.
First, we have to calculate the normal stress using
σ = F/A where F = Force acting on the Cross-sectional area
A = Area
Area is calculated as πd²/4 where d = 0.015m
A = 22/7 * 0.015²/4
A = 0.000176785714285m²
A = 1.768E-4m²
So, stress. σ = 300N/1.768E-4m²
σ = 1696832.579185520Pa
σ = 1.697MPa
Calculating E(long)
E(long) = σ /Ep
E(long) = 1.697E-3/2.70
E(long) = 0.0006285
At this point, we fan now calculate the change in length of the element;
∆L = E(long) * L
∆L = 0.0006285 * 200mm
∆L = 0.1257mm
Calculating E(lat)
E(lat) = -np * E(long)
E(lat) = -4 * 0.0006285
E(lat) = -0.002514
At this point, we can now calculate the change in diameter of the element;
∆D = E(lat) * D
∆L = -0.002514 * 15mm
∆L = -0.03771mm
They do in fact heat up while receiving energy.