Correct Answer: A. 4.55ms^-1

Explanation

\(M_1V_1 + M_2U_2 = V(M_1 + M_2)\)

5 x 10 + 6 x 0 = V(5 + 6)

V = \(\frac{50}{11} = 4.55\)m/s

Correct Answer: B. 1, 4

Explanation

when y = 0, value of x = roots of the equation

x² - 5x + 4 = 0

x = 1, 4 (see graph)

Explanation

(a)(i) Appreciation in agricultural practices refers to the gain or increase in the value or worth of an asset as the asset is being used over time e.g growing crops, young farm animals, cash crops appreciate.

(ii) Depreciation refers to the loss or reduction in the value or worth of an asset as the asset is being used overtime. e.g Tractor, drinkers, tools, implements do depreciate.

(iii) Salvage value: This is the amount which an asset is sold off when it is longer economical to keep or when the cost of maintenance of the asset is too high.

(b)(i) The salvage value of the tractor N3,000.00 i.e. the price at which e tractor was sold off.

(ii) Total depreciation = Cost price - salvage value of the tractor = N12,000.00- N3,000.00 = N9,000.00

(iii) Annual depreciation = total depreciation/no of years OR = Cost price - Salvage value/life span of tractor = N12,000/1987 - N3000/1978 =N9000/9years = N1000.

(iv) Appreciation: The tractor suffered a loss or reduction in worth. 9 years. Therefore, appreciation is nil.

Explanation

(a) Soil pH: (i) Is the concentration of hydrogen ions (H-) in the soil. (ii) determines the acidity, alkalinity or neutrality of the soil (iii) dictates crops grown/distribution. (iv) crops thrive well within pH range of 5.5 - 7.5 (v) It influences availability of nutrients for plant growth. (vi) influences the types and number of organisms in the soil

(b) Soil Texture (i) refers to the relative proportion of different sizes of mineral particles in the soil. (ii) This includes sand, silt and clay (iii) it determines the degree of coarseness or fineness of a soil sample/or soil consistency. (iv) the proportion of the different fractions determines the type of the soil. (v) coarse sand: 2.0 - 0.2mm, fine sand : 0.2 - 0.02mm, silt: 0.02 - 0.002mm, clay: less than (vi) soil texture tends to be the most consistent physical property (vii) determines the types of crops to be grown.

(c) Soil Organisms: (i) include micro and macro soil-living organisms, (micro cannot be seen with naked eyes, while macro can be seen (ii) soil organisms are involved in the decomposition of dead organic matter in the soil. iii are bacteria, fungi and algae. (iv) assist in other chemical changes as in the carbon and nitrogen cycles. (v) Also helps in burrowing, which paves way for aeration and movement of water in the soil. (vi) earthworms, termites, ants and others others are also important in the decomposition of plant residues in the soil. (vii) some bacteria fix atmospheric nitrogen while living in a host plant, usually a leguminous plant, e.g. Rhizobium inhabiting the root nodules (viii) some soil micro-organisms help improve soil structure. (ix) some soil micro-organisms can be harmful/destructive. (x ) some soil micro-organisms produce acidic materials which help to break down rocks.

(d) Soil Profile: Vertical section of the soil from the surface into the underlying unweathered materials. - The different soil colour and texture between each layer of soil are recognised and referred to as horizons. - The A - Horizon (or Top Soil) is made up of partly decayed plant and animal materials and humus. This portion is dark in colour. - The B-Horizon or Sub-soil contains mineral elements and clay. The colour is greyish or brown. - The C-Horizon or Weathered Parent Material is made up of materials produced from the parent rock. It has high clay materials. - The last layer, called D - Horizon or Bed rock is unweathered rock.

Correct Answer: B. 3.35 years

Explanation

Mean(age) = \(\frac{(1 \times 2) + (2 \times 3) + (3 \times 5) + (4 \times 6) + (5 \times 4)}{2 + 3 + 5 + 6 + 4}\)

= \(\frac{2 + 6 + 15 + 24 + 20}{20}\)

= \(\frac{67}{20}\)

= 3.35yrs

Correct Answer: A) all parts of the earth where life exists.

Correct Answer: C. who called them is holy

Correct Answer: A) the constituents of air are in a fixed proportion by mass

Correct Answer: B. jobbers

Correct Answer: A. enraged