Answer:
A. False
B. False
C. True
D. True
E. True
F. True
Explanation:
A. The equation Ax=b is referred to as a matrix equation and not vector equation.
B. If the augmented matrix [ A b ] has a pivot position in every row then equation Ax=b may or may not be consistent. It is inconsistent if [A b] has a pivot in the last column b and it is consistent if the matrix A has a pivot in every row.
C. In the product of Ax also called the dot product the first entry is a sum of products. For example the the product of Ax where A has [a11 a12 a13] in the first entry of each column and the corresponding entries in x are [x1 x2 x3] then the first entry in the product is the sum of products i.e. a11x1 + a12x2 +a13x3
D. If the columns of mxn matrix A span R^m, this states that every possible vector b in R^m is a linear combination of the columns which makes the equation consistent. So the equation Ax=b has at least one solution for each b in R^m.
E. It is stated that a vector equation x1a1 + x2a2 + x3a3 + ... + xnan = b has the same solution set as that of the linear system with augmented matrix [a1 a2 ... an b]. So the solution set of linear system whose augmented matrix is [a1 a2 a3 b] is the same as solution set of Ax=b if A=[a1 a2 a3] and b can be produced by linear combination of a1 a2 a3 iff the solution of linear system corresponding to [a1 a2 a3 b] takes place.
F. It is true because lets say b is a vector in R^m which is not in the span of the columns. b cannot be obtained for some x which belongs to R^m as b = Ax. So Ax=b is inconsistent for some b in R^m and has no solution.
Answer:
The two of the following measurements, when taken together, would allow engineers to find the total mechanical energy dissipated during the skid
B. The contact area of each tire with the track.
C. The co-efficent of static friction between the tires and the track.
D. The co-efficent of static friction between the tires and the track.
Explanation:
Answer:
option (b)
Explanation:
According to the Pascal's law
F / A = f / a
Where, F is the force on ram, A be the area of ram, f be the force on plunger and a be the area of plunger.
Diameter of ram, D = 20 cm, R = 20 / 2 = 10 cm
A = π R^2 = π x 100 cm^2
F = 3 tons = 3000 kgf
diameter of plunger, d = 3 cm, r = 1.5 cm
a = π x 2.25 cm^2
Use Pascal's law
3000 / π x 100 = f / π x 2.25
f = 67.5 Kgf
Answer:
To calculate the age of a piece of bone
Explanation:
Carbon 14 is an isotope of carbon that is unstable and decays into Nitrogen 14 by emitting an electron. The decay rate of radioactive material is normally expressed in terms of its "half-life" (the time required by half the radioactive nuclei of a sample to undergo radioactive decay). The nice thing about carbon 14 is that its "half-life" is about 5730 years, which gives a nice reference to measure the age of fossils that are some thousand years old.
Carbon 14 dating is used to determine the age of objects that have been living organisms long ago. They measure how much carbon 14 is left in the object after years of decaying without having exchange with the ambient via respiration, ingestion, absorption, etc. and therefore having renewed the normal amount of carbon 14 that is in the ambient.
A rock is not a living organism, so its age cannot be determined by carbon 14 dating.
