General Science Mixed Quiz: Set 72

The stone takes 2 s to fall 20 m, and in that time it moves 12 × 2 = 24 m sideways.

Accelerators speed up the vulcanisation of rubber; they are not a part of paint.

At the top of its flight all the kinetic energy of the ball has turned into gravitational potential energy. The mass is 350 g, that is 0·35 kg.

The tiny pores on the surface of a leaf, found mostly on its lower side, are called stomata. Each stoma is a slit guarded by two bean shaped guard cells, which swell to open it and shrink to close it.

The body's weight stays the same, but standing puts it on the small area of the feet, so the pressure is greater.

Hooke's law holds only as far as the limit of proportionality, and that limit is either equal to or lower than the elastic limit, so statements 1 and 4 are the correct pair.

Heat, by definition, is energy that flows because of a temperature difference. Thermodynamics recognises two ways in which a system can exchange energy with its surroundings: heat and work.

A simple pendulum about one metre long completes one full swing in roughly two seconds, and a pendulum of this length is called the seconds pendulum.

To see one's full image in a plane mirror, the mirror must be at least half the person's height: half of 1·5 m is 0·75 m. Light from Sita's feet must reflect from the mirror into her eyes, and so must light from the top of her head.

A qubit, short for quantum bit, is the basic unit of information in a quantum computer.

In a short circuit the live and neutral wires touch, the resistance of the path falls almost to zero, and the current shoots up.

Hydra is the one animal in the list that reproduces both by budding and by regeneration. In budding, a bulge grows out from the body wall of the parent Hydra, develops a mouth and tentacles, and then breaks off as a small independent Hydra.

All three symbols come from the Latin names of these metals: aurum, stannum and plumbum. Many metals known since ancient times take their symbols from Latin rather than English.

A bacterial flagellum is built of exactly these three parts. The filament is the long thread outside the cell, made of the protein flagellin coiled into a hollow helix, and it acts like a propeller.

The balanced equation is Fe2O3 + 3CO → 2Fe + 3CO2, which has equal numbers of every atom on both sides.

A ligament is the connective tissue that joins one bone to another at a joint. It is very elastic and strong, and it holds the bones in place so that a joint can move without the bones slipping apart.

The lower the pH, the stronger the acid, and pH 0 lies at the most acidic end of the common scale.

Copper exposed to moist air slowly gains a green layer of basic copper carbonate, a form of cupric carbonate. Copper does not rust like iron, but it corrodes.

Graphite has free electrons that can move through it, so it conducts electricity; diamond and fullerene do not conduct well.

The plasma membrane is made of lipids and proteins and contains no DNA or RNA. The plasma membrane is the outer boundary of the cell.