Pakistan MCQs

Gravitational field strength is g=F/m.
Its unit is N/kg, equivalent to m/s².

Use F=Gm₁m₂/r².
F=6.67×10^-11×2×3 = 4.002×10^-10 N.

Gravitational potential is a scalar quantity.
It represents work per unit mass associated with position.

Gravitational force varies inversely with distance squared.
Doubling distance multiplies force by 1/2² = 1/4.

Orbital objects still experience gravity.
They appear weightless because all parts accelerate together.

Field strength is force per unit mass.
G=20/4 = 5 N/kg.

Escape velocity depends on the body's mass and radius.
It is independent of the escaping object's mass.

Density measures how much mass is contained in a given volume.
Its SI unit is kg/m³.

Pressure describes how force is distributed over a surface.
Its SI unit is the pascal.

Pascal's principle is used in hydraulic machines.
The same pressure can produce different forces on different piston areas.

Immersion displaces fluid and creates an upward resultant pressure force.
That force equals the displaced fluid's weight.

A floating object displaces enough fluid for buoyancy to equal its weight.
The submerged fraction depends on relative density.