In this question, we are missing some of the information that is necessary in order to answer this question properly. However, we can look at what a relational database is in order to help you answer the question on your own.
A relational database is a set of tables from which data can be accessed. This can take place even without the need to reorganize the database tables. The programming interface of a relational database is the Structured Query Language (SQL). This approach was invented by E. F. Codd, who came up with it in 1970 while he was a programmer at IBM.
Answer:
Answer is c Heisenberg's uncertainty principle
Explanation:
According to Heisenberg's uncertainty principle there is always an inherent uncertainty in measuring the position and momentum of a particle simultaneously.
Mathematically

here 'h' is planck's constant
Answer:
a) benzene = 910 days
b) toluene = 1612.67 days
Explanation:
Given:
Kd = 1.8 L/kg (benzene)
Kd = 3.3 L/kg (toluene)
psolid = solids density = 2.6 kg/L
K = 2.9x10⁻⁵m/s
pores = n = 0.37
water table = 0.4 m
ground water = 15 m
u = K/n = (2.9x10⁻⁵ * (0.4/15)) / 0.37 = 2.09x10⁻⁶m/s
a) For benzene:

The time will take will be:

b) For toluene:


Answer:
The answer is 380.32×10^-6
Refer below for the explanation.
Explanation:
Refer to the picture for brief explanation.
Answer:
Yes, fracture will occur
Explanation:
Half length of internal crack will be 4mm/2=2mm=0.002m
To find the dimensionless parameter, we use critical stress crack propagation equation
and making Y the subject

Where Y is the dimensionless parameter, a is half length of crack, K is plane strain fracture toughness,
is critical stress required for initiating crack propagation. Substituting the figures given in question we obtain

When the maximum internal crack length is 6mm, half the length of internal crack is 6mm/2=3mm=0.003m
and making K the subject
and substituting 260 MPa for
while a is taken as 0.003m and Y is already known

Therefore, fracture toughness at critical stress when maximum internal crack is 6mm is 42.455 Mpa and since it’s greater than 40 Mpa, fracture occurs to the material