For upward acceleration a the effective gravitational field is g+a, so hydrostatic pressure at depth h is hρ(g+a).

Speed increases by v² = v0² + 2gs: v = 5 m/s at 0.8 m below; continuity gives A = A0·v0/v = 2.5·3/5 = 1.5 cm².

A light year is approximately 9.5 × 10^15 meters, so option B is the correct magnitude.

Energy should be expressed as kg m2 s-2 (or Joule), so 'kg m-sec' is incorrect while the others are correct.

The SI base unit of luminous intensity is the candela, defined as luminous intensity in a given direction of a source emitting monochromatic radiation.

As indicated in the OCR answer hint, the selected classification in the text is 'brittle' for solids that rupture above the elastic limit.

The moment (angular momentum/torque) of a spinning body has direction as well as magnitude, so it is a vector, unlike the scalar quantities listed.

OCR indicates option B (10^3 mm) as selected; 1 metre = 1000 mm (10^3 mm).

Apparent weight = actual weight − weight of displaced water; displaced water mass equals 100 g, so immersed weight = 101 − 100 = 1 g.

Angular momentum has SI units equivalent to energy × time, i.e., joule-second (J·s), hence option C is correct.