Explanation

(a) Principle of conservation of linear momentum states that if two or more bodies collide in a closed system, the total momentum after the collision is equal to the total momentum before the collision.

(b) The principle of action of a propelled rocket is that gas burnt within the combustion chamber of the rocket engine is expelled downwards through the exhaust (tail nozzle) at very high speed, hence an equal and opposite momentum is given to the rocket which moves the rocket upward.

(c) The motion is not simple harmonic because:

-there is no equilibrium position

-acceleration of the ball is not directly proportional to displacement

-acceleration of the ball is not directed towards a fixed point.

(d)(i) Both balls will hit the ground at the same time.

(ii) All free falling objects fall at the same rate because they are pulled towards the earth by gravity and accelerate at a constant rate.

(e)(i) Charge in momentum = m(v-u)

= 0.10(13 - 17) = 3 kgms\(^{-1}\)

(ii) Average force F = \(\frac{\text{change in momentum}}{\text{time}}\) = \(\frac{3}{0.15} = 20N\)

Correct Answer: C. fall upon his face in awe

Correct Answer: B. DNA polymerase I

Explanation

While all the answer choices are important in DNA replication, only DNA Polymerase I performs this particular function. Ligase helps bind the newly replaced DNA nucleotides to the rest of the DNA strand. DNA polymerase III is the main synthesizing enzyme of DNA replication, and creates the majority of the DNA strand. DNA polymerase II is less well known than I and III, but it is believed to perform as a repair enzyme which removes incorrectly paired segments of DNA (which can then be filled back in by DNA polymerase I).

Correct Answer: A. 235°

Explanation

Reflex ∠WQS = 360° - (55° + 70°) =360° - 125° = 235°

Correct Answer: B. collective bargaining

Explanation

Collective bargaining is a process of negotiation between employers and a group of employees aimed at agreements to regulate working salaries, working conditions, benefits, and other aspects of workers' compensation and rights for workers.

Correct Answer: B. radar

Explanation

The words 'annoy', declare', and 'believe' have their stress on the second syllable, while 'radar' has its stress on the first syllable. Therefore, 'declare' has a different stress pattern.

Correct Answer: C. 21

Explanation

using the trial method by inserting each option in the equation.

Inserting 21º: sin([5 x 21] - 28) = cos([3 x 21] - 50)

sin(105 - 28) = cos (63 - 50)

sin 77º = cos 13º

where:

sin 77º = 0.9744

cos 13º = 0.9744

Correct Answer: A) 2.7g

Explanation

(a) Sexual reproduction in Rhizopus - By conjugation;

• It is usually between two strains of hyphae
• Known as + and - plus and minus/ opposite mating types
• The hyphae come in contact
• And produce small projections of their walls
• Which develop into progametangia with several nuclei
• The two progametangia enlarge
• Each progametangium develops a cross wall to divide into two parts; the gametangium and suspensor
• Subsequently the wall dissolves/breaks; and their contents/nuclei fuse to form a zygote
• The zygote develops a thick wall to form a resistant zygospore
• The zygospore germinates during favourable / damp / wet condition
• Into hyphae which bear sporangia.

(b) (i) Name of hormone Adrenalin /Adrenaline

(ii) Part where hormone is produced Adrenal gland/Medulla.

(iii) Changes that must have taken place as a result of the hormone

• Increase in heart beat
• Increase in rate of respiration
• Arterioles of skin and alimentary canal constrict
• Dilation of blood vessels that cause more blood to flow to the muscles/heart/lungs
• Increase in muscular tone/voluntary muscles become tensed
• Glycogen is converted to glucose/increase in blood sugar level
• To produce more energy
• Dilation of pupils of the eye
• Momentary freight/fear/anxiety/heavy breathing
• Spleen releases more Red Blood Cells from its reserve
• Increase in blood pressure

(c) (i) Differences between excretion in flowering plants and excretion in humans.

(ii) Organelles in plant cells responsible for excretion of metabolic wastes.

Mitochondrion/ mitochondria; chloroplast/ chloroplasts.

Correct Answer: D. ?2

Explanation

An Isosceles Right Triangle is a right triangle that consists of two equal length legs.

i.e opp = adj

hyp\(^2\) = adj\(^2\) + opp\(^2\)

2\(^2\) = x\(^2\) + x\(^2\)

4 = 2x\(^2\)

2 = x\(^2\)

√2 = x